If you are using the TGP to paint and SPI, you HAVE to then slave your MAVs to your SPI. It doesn't do it by itself, you have to do it manually every time.
An alternate method, is to simply point your nose at the target and slew your MAVs with your stick, if that makes sense. That's actually in the manual. Although, this is probably a last resort method, simply because you have to be close enough to see your target with your own eyeballs.....which means they can see you.....which is never really a good thing. Using your TGP to slave your MAVs is probably the best method, though. You can take your time and keep your distance while sorting yourself out.