Thanks for asking the questions! Once you got cauldron, you can still use the old editor. Cauldron uses JavaScript and HTML. And cauldron has all the palletes on castle (you won’t have them on the old editor btw), not only that but, you can even put custom colors!
The only thing I know is that I never remember having an editor in Castle that uses Java programming, and that after the cauldron form is accepted, Castle will notify you and the cauldron will appear in the kits section