As a MIDI noob, I didn't undertake this until recently. Works like a charm: surprised!
I am now setting the TEMPO on my Axe FXIII by sending RAW MIDI from Bandhelper. Maybe there is an easier way, but I have created Midi Presets for Tempos that we use, and add the proper MIDI Preset to each song
Example: my midi preset file named 'TEMPO120' has this in the RAW MIDI (HEX Code) box:
F0 00 01 74 10 14 78 00 79 F7
where F0 00 01 74 10 is the Fractal Audio company code
14 is the cc I want
78 00 sets value at 120 bpm
79 is the XOR checksum
Works great! BTW - had to leave the RAW MIDI DEVICE pulldown as undefined - just didn't work for me. YMMV...