To preface version 1.4.10 works fine, so the cause is probably some change in 1.4.11. The game crashes on startup with some of my mods. I know the cause is not Pneumatic Craft mentioned in crash log, because removing it simply changes it to some other mod (occultism in this case). The crash log is below, together with latest log. I am using Forge 31.2.30 on Minecraft 1.15.2.
Crash:
https://paste.ubuntu.com/p/525JXVCWwz/
Latest:
https://paste.ubuntu.com/p/qnw6Hgy6zM/

Botania appears to be installed. I added Botania support in the newer versions but maybe I didn't handle the versions correctly.

Yes I have Botania. Unfortunately it is my private modpack and I don't know how to share it.

I have removed Botania and can confirm that the game loads up properly without it (when on 1.4.12 version).

I'm able to launch the game with only Botania and Astral and their dependencies. Can you check if that works for you and if so, can you see which other mod will cause the game to crash when those two are installed? I think one mod is changing how registries are loaded which is causing the crash.

Is the modpack you're on a public modpack that I could download?

Ok after gradually removing all the mods until it stopped crashing I've found the combination of mods that causes the crash and yes it is quite a combination. Removing any one of them results in the crashing not occurring. Only all of them together crash as far as I can see (the latest log of crash https://pastebin.com/d88Pyb6k). I got all of these mods from Enigmatica 5 modpack, which you can download from Curseforge.
ftb-gui-library-1.0.0.14
tombstone-4.4.1-1.15.2
ftb-ranks-1.0.0.3
ftb-teams-1.0.0.5
ftb-chunks-1.1.0.12
corail_woodcutter-1.1.3-1.15.2
ftb-backups-2.1.0.1
corail_recycler-4.0.5-1.15.2
Plus Botania, Astral and their dependencies:
astral-1.4.12
curios-FORGE-1.15.2-2.0.2.4
Botania-r1.15-387
Patchouli-1.15.2-1.2-34

I can't find either of the corail mods online

They should be in mods folder after downloading Enigmatica 5. AFAIK they are not on Curseforge at the moment. They are external mods added to the pack.
Edit: Actually I can't find them anywhere either right now. The server files for Enigmatica have only Corail woodcutter.

OK. Apparently Corail_31 mods are deleted due to some drama. I do have local copies of those mods, but from what I understood they are not coming back.

Since the mod combination is no longer possible, if it okay if I close the issue until this occurs again with another combination of mods?

Sure, go for it. No point in fixing bugs that no-one will encounter.

Someone else had this issue. I don't know why DeferredRegister causes crashes with certain mod combinations, but switching to another form of registering may have fixed the issue.

https://www.curseforge.com/minecraft/mc-mods/ma-astral/files/3000084

Feel free to close the issue if the issue gets fixed with the new version