The mod causes a crash when I use any resource pack that changes the player animations using entitymodelfeatures/texturefeatures.
Showcase of this function : https://youtu.be/CaijC8gA_m8?si=cTOvMQE3cUxTMeoq
I really hope compatibility will get looked into. But no stress! Take the time you need.
Relevant logs :
[19:04:23] [Render thread/ERROR]: Reported exception thrown! net.minecraft.class_148: Rendering entity in world at net.minecraft.class_898.method_3954(class_898.java:176) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_761.method_22977(class_761.java:1574) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_761.method_22710(class_761.java:1324) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_757.method_3188(class_757.java:1110) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_757.method_3192(class_757.java:880) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_310.method_1523(class_310.java:1219) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_310.method_1514(class_310.java:802) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.client.main.Main.main(Main.java:250) ~[1.20.1-0.24.0.jar:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:?] at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:?] at java.lang.reflect.Method.invoke(Unknown Source) ~[?:?] at org.quiltmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:551) ~[quilt-loader-0.24.0.jar:?] at org.quiltmc.loader.impl.launch.knot.Knot.launch(Knot.java:84) ~[quilt-loader-0.24.0.jar:?] at org.quiltmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:28) ~[quilt-loader-0.24.0.jar:?] Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 at java.util.ImmutableCollections$ListN.get(Unknown Source) ~[?:?] at net.minecraft.class_630.method_22700(class_630.java:181) ~[minecraft-1.20.1.i0:0/:?] at com.unascribed.ears.EarsFeatureRenderer$1.doAnchorTo(EarsFeatureRenderer.java:98) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.EarsFeatureRenderer$1.doAnchorTo(EarsFeatureRenderer.java:82) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.common.render.AbstractEarsRenderDelegate.anchorTo(AbstractEarsRenderDelegate.java:106) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.common.EarsRenderer.renderInner(EarsRenderer.java:245) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.common.EarsRenderer.render(EarsRenderer.java:63) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.common.EarsCommon.render(EarsCommon.java:142) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.common.render.IndirectEarsRenderDelegate.render(IndirectEarsRenderDelegate.java:35) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.common.render.IndirectEarsRenderDelegate.render(IndirectEarsRenderDelegate.java:23) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.EarsFeatureRenderer.render(EarsFeatureRenderer.java:71) ~[ears-1.4.6.i0:0/:?] at com.unascribed.ears.EarsFeatureRenderer.method_4199(EarsFeatureRenderer.java:58) ~[ears-1.4.6.i0:0/:?] at net.minecraft.class_922.method_4054(class_922.java:145) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_1007.method_4215(class_1007.java:66) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_1007.method_3936(class_1007.java:43) ~[minecraft-1.20.1.i0:0/:?] at net.minecraft.class_898.method_3954(class_898.java:145) ~[minecraft-1.20.1.i0:0/:?] ... 14 more

I have the same issue but with the "Fresh Moves" Resourcepack (https://modrinth.com/resourcepack/tras-fresh-player). It crashes when I go into third person.
Relevant logs:
[13:22:18] [Render thread/ERROR]: Reported exception thrown! net.minecraft.class_148: Rendering entity in world at net.minecraft.class_898.method_3954(class_898.java:177) ~[client-intermediary.jar:?] at net.minecraft.class_761.method_22977(class_761.java:1346) ~[client-intermediary.jar:?] at net.minecraft.class_761.method_22710(class_761.java:1103) ~[client-intermediary.jar:?] at net.minecraft.class_757.method_3188(class_757.java:1093) ~[client-intermediary.jar:?] at net.minecraft.class_757.method_3192(class_757.java:858) ~[client-intermediary.jar:?] at net.minecraft.class_310.method_1523(class_310.java:1320) ~[client-intermediary.jar:?] at net.minecraft.class_310.method_1514(class_310.java:888) [client-intermediary.jar:?] at net.minecraft.client.main.Main.main(Main.java:265) [client-intermediary.jar:?] at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:470) [fabric-loader-0.15.11.jar:?] at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74) [fabric-loader-0.15.11.jar:?] at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23) [fabric-loader-0.15.11.jar:?] at org.prismlauncher.launcher.impl.StandardLauncher.launch(StandardLauncher.java:100) [NewLaunch.jar:?] at org.prismlauncher.EntryPoint.listen(EntryPoint.java:129) [NewLaunch.jar:?] at org.prismlauncher.EntryPoint.main(EntryPoint.java:70) [NewLaunch.jar:?] Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 at java.base/java.util.ImmutableCollections$ListN.get(ImmutableCollections.java:687) ~[?:?] at net.minecraft.class_630.method_22700(class_630.java:179) ~[client-intermediary.jar:?] at com.unascribed.ears.EarsFeatureRenderer$1.doAnchorTo(EarsFeatureRenderer.java:100) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.EarsFeatureRenderer$1.doAnchorTo(EarsFeatureRenderer.java:84) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.common.render.AbstractEarsRenderDelegate.anchorTo(AbstractEarsRenderDelegate.java:106) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.common.EarsRenderer.renderInner(EarsRenderer.java:353) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.common.EarsRenderer.render(EarsRenderer.java:63) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.common.EarsCommon.render(EarsCommon.java:142) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.common.render.IndirectEarsRenderDelegate.render(IndirectEarsRenderDelegate.java:35) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.common.render.IndirectEarsRenderDelegate.render(IndirectEarsRenderDelegate.java:23) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.EarsFeatureRenderer.render(EarsFeatureRenderer.java:73) ~[ears-fabric-1.20.6-1.4.6.jar:?] at com.unascribed.ears.EarsFeatureRenderer.method_4199(EarsFeatureRenderer.java:60) ~[ears-fabric-1.20.6-1.4.6.jar:?] at net.minecraft.class_922.method_4054(class_922.java:149) ~[client-intermediary.jar:?] at net.minecraft.class_1007.method_4215(class_1007.java:68) ~[client-intermediary.jar:?] at net.minecraft.class_1007.method_3936(class_1007.java:45) ~[client-intermediary.jar:?] at net.minecraft.class_898.method_3954(class_898.java:143) ~[client-intermediary.jar:?] ... 13 more

Can confirm the same, it seems to be something with how anything messes with the default player model.
Tested with Expressive Fresh Moves v3.0.1 and game crashes.
Mods used (primarily for fresh moves):
Entity Texture Features v6.0.1
Entity Model Features v2.0.2