Hello. I use shaders a lot, so do many people playing this one modpack (1.19.2) I found. What we realized is that Skyweave does not render, at all, when using shaders (Iris port to Forge, not optifine, although I wouldn't know if it happens with optifine as well).

Now, I went digging through the files, and while I can't read code much, I did compare normal shader core files vs the ars nouveau shader core files, and what I found is that the sky.json file refers to ars_nouveau:sky instead of minecraft:core/position for rendering the sky.

Once again, I do not know how to code, I just am decent at doing research and comparing stuff. But, maybe this would be how one would fix it? That is, making sure that ars_nouveau:sky is seen as minecraft:core/position despite being different. Cheers.

Shaders disable and replace the main vanilla shader pipeline, custom rendering has to be built just to accommodate for them which I am not willing to commit time for, sorry.

Looks like at some point within the last few months, you can now turn on "unknown shaders" by pressing CTRL-G

within the shaderpack menu. This actually lets the Skyweave and Portal blocks to be seen....however jank it may be LOL. Perhaps if more people ask for this, tell them to enable unknown shaders?