CTA has been updated for the first time in a little while, now allowing use in 1.21.5 and a new feature: Colored water in cauldrons! (With thanks to eccentric_nz for the inspiration)
The new features can be used but this is not necessary, when loading the plugin it will resort to custom textures being disabled.
In the config file you can turn on custom models and with a quick reload and with the texture pack you can now have custom colored water for each potion type!
Bugs fixed:
Right clicking with tipped arrows would fill up cauldron and give empty bottle
Another quick update on the development front, this plugin version is temporary, right now cauldron values are stored in the plugin folder, this will soon change. Changing this should improve the stability of this plugin (which has not been an issue on my end so far but may happen in very specific situations).
This change will come out soon but for now, enjoy this plugin for version 1.20.1!