RE: JR XF631
The short answer is yes. There is a seperate dedicated flap switch and if you have a seperate flap servo it is just a straight forward connect. You can also use the flaperon setting which will partially deploy your ailerons as flaps.
Just follow the instructions in the book (they can be a little confusing) with Tx and Rx on to make sure you are getting the movement you require.
Cheers,
Colin