The updater wasn't really broken, but the Spigot cache for version takes a while to update so the plugin would show theres a new update even when you have the latest version for a little while because I was just comparing the versions outright and ignoring being a higher version.
TL;DR the version checker will always be accurate now

someone reported a bug with HMCCosmetics, and after looking into it it turns out Paper doesn't support hiding item attributes with item flags when the item only has the default item attributes. i don't really feel like applying a bandaid fix just to solve this (giving each item its default modifiers if it doesn't have any modifiers already just to hide them..), so Paper is not supported. however, i did come across an issue i could fix with hmccosmetics (and any other plugin who does something similar to them) and added the fix. let me know if anything breaks as a result of this change (it would involve equipment if so).