Indeed, unfortunately there is no magic shortcut for resaving a registration bank, but at least you can save some clicks.
Normal process is as follows:
(load registration bank and do some changes on one or more registrations)
1. Press the registration bar on top of the screen (or press both “Registration Bank Select” buttons together)
2. Press “File”
3. Press “Save”
4. Press “Save Here”
5. Press “OK”
6. Press “Yes” (to confirm the overwrite)
(load another registration bank)
My method is to systematically skip steps 1 and 2. You can make as many changes as you want to the current bank. You can switch off and on your keyboard (SX700 in my case): the changes in the current bank are maintained. The moment you try to load another registration bank, you are automatically prompted to save the current bank (= jump to step 3) and after step 6, your newly selected bank is already loaded.
