The following settings need to change:
- Turn on Send on Preset Change and Update on Preset Change for each of those buttons
- The buttons need to be assigned to the same group number
- In Globals, the group needs to have "Send Off Messages" turned off
- Make sure you have a button set up as IA Store. On the PBC/6X by default, holding the Function button does this. On the PBC/10 holding the Loops button does this. You probably have a custom page for these buttons, make sure that there's an IA store button there.
Once you do this, those buttons will have precedence over the PC specified in your preset, so if you want to have the preset's PC sent, make sure all of the buttons are saved in the Off state for that preset.