Radiant specifically licenses a key for either table or quick. If you are switching between both, you may have purchased a combo key license. That means a typical user can't just switch as Aloha Manager and the terminals will state "Licensed for Quick Service Only."
On Switching from QS and TS, they share about 90% of the same features. However, if the intent is to build a new concept or database, it is often easier to start with a clean database.