The proper way, as taught to me by a Thai, to flag down a Baht Bus is to hold your right arm straight out in a somewhat down position. Not to hold it up and wave to the driver. Of course anything works. The price is 10 Baht but that does not mean you can't give more. Often on a longer ride, especially when the bus is nearly empty, I give 20 Baht and once gave 100 Baht during the lean times of Covid when one driver and his family provided me a ride in an empty bus..They were grateful.
As for deviating from the "regular" route, that is quite often coming from Jomtien to Pattaya at Pattaya Tai. Often the drivers will turn into Pattaya Tai and then make a U turn and go back toward Jomtien.