I am on 1.20.1 and it loads without json things but breaks some tags

At a quick glance, you declared your dependencies wrongly in 1.20.1 in mods.toml. They are declared as dependencies.tinkers_things instead of dependencies.tinkers_katanas so they are ignored if tinkers_things is not installed.

They were declared right in 1.19.2. Source seems to be missing from github for 1.20.1

I forgot to update the github page, that's my bad. I'll fix that and the dependency issue as soon as I get home.