Yeah this is key - in order to get out of full-screen you have to find and navigate some some ini file, then its still doing the mouse capture thing, which I think is also a setting, but all this faffing about just to get it into a usable state is pretty user hostile

I want the window to be open like any other window, and the mouse pointer to work transparently in and out of it - like when I hover the mouse over the dosbox window, change the pointer but keep the same mouse speed, momentum etc

I think this would be really hard to do in an emulated environment, maybe even would require patching each game executable to get the mouse speed right (not sure?), the modern environment integration, like you say, is what Im after too