You are using the parameter “Send PC message on Activate” which is simply a toggle to send or not send the parameters you configured in the MIDI Out block.
If you are using GP3 and songs/setlists you can now send any kind of a MIDI message out for any song part. If not - you have two options.
- Instead of connecting your widgets to a MIDI OUT block - create a new MIDI IN block just for the purposes of sending the PC messages out, but block all incoming channels so you don’t accidentally send notes and other incoming midi data.

- Connect your widgets to this MID IN block CC0, CC32 and PC parameter

- Connect the MIDI IN block to MIDI OUT block.

That should work now.
Alternative #2 - Use GP Script and do whatever you like with MSB/LSB, PC messages under any conditions you want.
Hope this helps.