yes, banks work everywhere, with PRO version you can switch and edit them in the TIC's Editors
with sync() api you can load game resources like sprites/map/sound from a bank you want to the 80K RAM in runtime
you don't need to call sync() for the code, all the code automatically loads on game startup from 7th bank to 0
to edit banks in external editor pls use text cart format, switch bank in Code Editor, type some code, go to console and use 'save game.lua' command, then you can open 'game.lua' in any text editor (TIC will automatically reload cart when you save it), you should see <CODE1>... section