There isn’t a way to customize whether the Hotswitch/Performance switch functions in latching or momentary. Every algorithm was designed to be one or the other; where “Hotswitch” is used, it’s always latching. However, H9 has a function called “Expression Pedal Value” that will momentarily take your settings to the Max range settings of your expression ranges. This can be set to behave like a momentary Hotswitch. I explain in this video:
In addition, with an adequate controller, customizing latching/momentary functionality can be achieved via MIDI by programming press & release states per button.