When trying to load up 1.3.1-dev I get this crash which I assume means that this shaded method should be marked as remap = false

Oops, Recently I've change my buildscript and it upload dev artifact instead of production artifact :(.
Please redownload using this link, once curseforge is approved.
https://legacy.curseforge.com/minecraft/mc-mods/stevekungs-lib/files/5064118