Not sure where the problem with this is likely to be.  I have a StreamDeck profile with Event buttons that send one event on press and a different event on long press. The buttons work fine on a hardware SD-XL but don't work on SD Mobile. I've tried using both the long press down and up events but neither work.

Interestingly, if I have a button with just a keydown event the event is sent as soon as I touch the on-screen button. If I have a button with a keydown (event A) and a long-press keydown (event B) the event isn't sent until I take my finger off the button at which point event A is sent. I was expecting event B to be sent if the delay between touching the screen and removing my finger is longer than the long-press timeout of 750ms.

I'm sorry, but I know nothing about SD Mobile. I imagine that potentially they can't reliably split key down/up - or that there is an "auto-up" - or whatever else could be the matter with whatever mobile tech they are using. That is not unheard of.