example seed: -473343465897378388
Log (Fabric): https://mclo.gs/h5mDjcl
Log (Quilt): https://mclo.gs/0TlGiHS

When entering or being near a Snowy Hemlock Forest or Rainforest with Shaders enabled the game crashes pretty much right away, Sodium/Iris related?
If I set Shaders to disabled it doesn't crash.

Hemlock forests in general are very difficult for some graphics hardware. So although you could probably characterize it as a shader bug, it's really more of a hardware resource issue. Many folks have problems with that biome without shaders.

You might find the Cull Leaves mod helps.

Ah I see, thanks for the info. So maybe my 3GB of VRAM aren't enough or my card just too bad at doing what it needs to do?
In that case, fix would be buying a better card of course 👍🏻

I am not an expert in the graphics stuff, but as I understand it, Hemlock is particularly bad because the texture has complex transparency (lots of small areas you can see through it) and the biome generates such that you can see through many layers of hemlock leaves. This adds up to a very complicated occlusion calculation which can be quite taxing, and the reason Cull Leaves helps is it reduces the amount of layers of occlusion caused by looking through the Hemlock canopy from many to about one.

Fixed the crashes on my current hardware by installing the Cull Leaves mod you recommended and disabling "Fix Sodium Block Face Culling on Leaves" (Doesn't seem to be useful when using the default resource pack)
Sure it runs like terribly on 16 view distance on my PC but going for 10 while in the Forests really isn't bad at all.
Awesome looks and runs fine now 👍🏻