I am posting this issue on Origins page as well, as I do not know what the exact problem is.
I am playing on Minecraft 1.16.2.
Mods:
Fabric Loader v0.9.2+build.206
Fabric API v0.19.0+build.398
Origins v0.3.7
Elytra Bounce v0.1.0
When using Elytra Bounce with Origins, game crashes with this output:

[main/WARN]: @reDIrect conflict. Skipping elytra_bounce.mixins.json:LivingEntityMixin->@reDIrect::initAi(Lnet/minecraft/class_1309;IZ)V with priority 1000, already redirected by origins.mixins.json:LivingEntityMixin->@reDIrect::preventStoppingToFly(Lnet/minecraft/class_1309;IZ)V with priority 1000
Exiting with -1
org.spongepowered.asm.mixin.injection.throwables.InjectionError: Critical injection failure: Redirector initAi(Lnet/minecraft/class_1309;IZ)V in elytra_bounce.mixins.json:LivingEntityMixin failed injection check, (0/1) succeeded. Scanned 1 target(s). Using refmap elytra_bounce-refmap.json
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.postInject(InjectionInfo.java:408)
at org.spongepowered.asm.mixin.transformer.MixinTargetContext.applyInjections(MixinTargetContext.java:1291)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyInjections(MixinApplicatorStandard.java:1042)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:395)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:320)
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:345)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:570)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:351)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:191)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:178)
at org.spongepowered.asm.mixin.transformer.FabricMixinTransformerProxy.transformClassBytes(FabricMixinTransformerProxy.java:23)
at net.fabricmc.loader.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:157)
at net.fabricmc.loader.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:143)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at net.fabricmc.loader.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:156)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at net.minecraft.class_2246.(class_2246.java:99)
at net.minecraft.class_3523.(class_3523.java:13)
at net.minecraft.class_5471.(class_5471.java:11)
at net.minecraft.class_5458.method_30573(class_5458.java:44)
at net.minecraft.class_5458.method_30566(class_5458.java:75)
at java.util.LinkedHashMap.forEach(LinkedHashMap.java:684)
at net.minecraft.class_5458.(class_5458.java:74)
at net.minecraft.class_2378.(class_2378.java:237)
at net.minecraft.class_2966.method_12851(class_2966.java:42)
at net.minecraft.client.main.Main.main(Main.java:137)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:192)
at net.fabricmc.loader.launch.knot.Knot.init(Knot.java:140)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:26)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:196)
at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:231)
at org.multimc.EntryPoint.listen(EntryPoint.java:143)
at org.multimc.EntryPoint.main(EntryPoint.java:34)
Failed to start Minecraft:
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:196)
at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:231)
at org.multimc.EntryPoint.listen(EntryPoint.java:143)
at org.multimc.EntryPoint.main(EntryPoint.java:34)
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:194)
at net.fabricmc.loader.launch.knot.Knot.init(Knot.java:140)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:26)
... 8 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:192)
... 10 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:364)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:191)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:178)
at org.spongepowered.asm.mixin.transformer.FabricMixinTransformerProxy.transformClassBytes(FabricMixinTransformerProxy.java:23)
at net.fabricmc.loader.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:157)
at net.fabricmc.loader.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:143)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at net.fabricmc.loader.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:156)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at net.minecraft.class_2246.(class_2246.java:99)
at net.minecraft.class_3523.(class_3523.java:13)
at net.minecraft.class_5471.(class_5471.java:11)
at net.minecraft.class_5458.method_30573(class_5458.java:44)
at net.minecraft.class_5458.method_30566(class_5458.java:75)
at java.util.LinkedHashMap.forEach(LinkedHashMap.java:684)
at net.minecraft.class_5458.(class_5458.java:74)
at net.minecraft.class_2378.(class_2378.java:237)
at net.minecraft.class_2966.method_12851(class_2966.java:42)
at net.minecraft.client.main.Main.main(Main.java:137)
... 15 more
Caused by: org.spongepowered.asm.mixin.injection.throwables.InjectionError: Critical injection failure: Redirector initAi(Lnet/minecraft/class_1309;IZ)V in elytra_bounce.mixins.json:LivingEntityMixin failed injection check, (0/1) succeeded. Scanned 1 target(s). Using refmap elytra_bounce-refmap.json
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.postInject(InjectionInfo.java:408)
at org.spongepowered.asm.mixin.transformer.MixinTargetContext.applyInjections(MixinTargetContext.java:1291)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyInjections(MixinApplicatorStandard.java:1042)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:395)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:320)
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:345)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:570)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:351)
... 36 more
Process exited with code 255.

Looks like its fully incompatible... One client tries to override another client - thats pretty much unfixable.

Looks like its fully incompatible... One client tries to override another client - thats pretty much unfixable.

...what? that's very easy to fix
apace100/origins-fabric#27

also thanks for reminding me to close this issue

Looks like its fully incompatible... One client tries to override another client - thats pretty much unfixable.

...what? that's very easy to fix
apace100/origins-fabric#27

also thanks for reminding me to close this issue

What i meant was that the issue's author probably can't fix this unless they modify and build from source. Sorry for the confusion.