I've made 2 level editors so far in my games, and one thing that would speed things up for me is if the simulator could handle mouse events, since I have to make more levels.
ie:
function playdate.mousehandler(button, state, x, y)
-- buttons: 1=left, 2=middle, 3=right
-- states: 1=moving while released, 2=down, 3=moving while down, 4=just released
end