Thanks for your help on my previous post, that got me to the next step.

Is there anyway to get WinWin working with game maker's UI layers? 

I almost got it working with layer_script_begin and layer_script_end, but there's a flickering effect that I'm not sure how to resolve.

layer_script_begin("UILayer_1", function(){
        winwin_draw_begin(window); 
})

layer_script_end("UILayer_1", function(){
        winwin_draw_end();    
})

Here's a sample of the project if that's helpful: https://drive.google.com/file/d/1zlmBqwz1MG9vMRKiAKDRCZlkEv-HzaMv/view?usp=shari...

I think once the flickering is fixed it'll be pretty easy to get my ui elements working with the winwin mouse functions.  

Actually looks like this can be fixed by disabling the "optimizations for windowed games" as was recommended in the other post: https://itch.io/t/4513801/large-frame-jitter-while-having-a-very-small-extra-win...

Would be interested if this can work out of the box, but disabling that setting is sufficient to unblock me for development. 

Sometimes I feel like you can’t do anything remotely interesting without something weird happening at least on some of the computers