I did some digging, and it looks like WZ uses https://fengari.io/
to run LUA on browsers. The error:
pcall failure in function Client_GameRefresh ret=-1 TypeError: to_jsstring expects a Uint8Array
originates from line 61 of https://github.com/fengari-lua/fengari/blob/master/src/defs.js
That suggests that somewhere in the mod framework (so not the mods itself), something is trying to turn into a JS string that cant turn into a JS string. With that knowledge, we can answer the question:
Is it just Warzone getting covid, or do I have to modify my mod?
It's WZ getting covid.