With Fldigi to change modes in a macro. Setup a Qpsk macro with <MODEM:QPSK31> and a macro for BPSK with <MODEM:BPSK31>
Down at the very lower left there is a box that shows what mode you are using and if you click on that it will bring up the different sub mode, BPSK31, BPSK63, BPSK125 etc.
You can click on the sub mode you want and you're ready to go. Doing it that way, you won't have to go to the mode tab and do a bunch of hunting. You should be able to choose any mode in a second or two.