I think I have it now – I meant the hotswitch functionality base don the middle switch of the H9 Control App. I long press it, adjust the parameters and save it. Then it is assigned to my DMC-4 hotswitch button.
A further question though is which parameters in the algorithms have the freeze functionality? I notice 1 Blackhole patch which has Freeze on its feedback knob but it is infinite which adds more and more all the time.
Thanks for your assistance.