A lot of my show is just triggering Ableton to play the next scene which is one button. Is there a way to make my whole Block M one big button that I can smash with my palm? :-).
So in other words, I want all the pixels of my block to be one button and trigger a single MIDI note that I would map in Ableton to the "Scene Launch" button.
Yes, that's possible.
It would be relatively easy to script an app that does exactly this exclusively, but if you could live with a big button sending MIDI CC instead of a note, there is an app already available with which you can freely create up to 25 buttons and switches (faders and xyz pads, even) on the Lightpad, give them a size position, color and send behavior. An extremely versatile thing and works a charme. Of course it allows to create a single big button across the whole pad area, too. Check it out:
I use it without any issue for quite a while as a permanently loaded app on one of my Lightpads to control a bunch of key functions of my DAW. Even if it sounds a bit overkill for your particular usecase it should do the trick flawlessly - well, provided you can do what you want with a CC message coming in instead of a note, that is.
It comes in 3 flavors, one for buttons and switches only, a second can also spawn faders and the third one gives you the whole mcguffin including xyz pads. For your single button you'd choose the simplest variation obviously, called Dynamic Controls X.
Hope this helps.