bump, I would love for this to be fixed

I have no clue if this is fixable, but according to https://www.curseforge.com/minecraft/mc-mods/first-person-model?comment=34 the forge mod Advanced Skin Customization somehow is able to do it. I'll have to look into how he as done it, but probably you have to somehow re-enable the head after rendering the body, but before the shader is getting its data.

I have fixed the bug!!!
First I tried to turn it visible immediately after the render but id didn't work.
The optifine renders everything twice, one normally one shader. (I think)
My repository is https://github.com/KosmX/FirstPersonModel-Fabric

I fixed another bug: if I don't have a helmet one will randomly disappear.

Oh neat. Open a pull request(or I will) and then I'll check out the changes and release the fixed version 👍

I opened a pull request.