Kodachrome

I can provide a list of server software and plugins that I've been able to reproduce the bug with. I understand once you have to go through so much effort to reproduce a bug, it can become unmotivating to fix, however again this happens on a vanilla client despite the modified server, so this can only really be fixed by Mojang. I've asked around and no one else on the server has been able to reproduce the issue, so it is at least somewhat hardware/software environment based (despite my fairly standard setup). So I'll ask the mods, is it worth reeopning this issue or creating a new ticket, or is it likely this will be marked as won't fix and well... won't ever be fixed.

Is it not worth looking into though? If this is a client bug then no one can fix it but Mojang

Sorry to comment on an invalid issue, I will create a new one if needed. I happen to have a similar bug on an unmodified client. The strange part about it is, it seems to be world based. I have only ever been able to produce this bug on one specific public server. This bug seems to trigger randomly while playing, and persists through all 1.16 versions and even after I reinstalled Minecraft and deleted all the data. While both times the bug was triggered while I was using a modified client, as I said it persists even on unmodified ones.
When this bug has been triggered on an account, one of two things will happen when trying to craft without the recipe book open. Either the game will crash, or a strange visual glitch with the recipe book will occur. (Crash log and screenshot attached)