1+ to this feature, I’m pretty new to animation and art, pixel or otherwise, but at least to me it seems very important to be able to have the same animation open on multiple stages of the animation and on multiple levels of zoom just to easily get an overview of the different states and how they relate to the part you are drawing. Understand it hasn’t been prioritised given the complexity though.
But instead of just complaining I’ll also come with a possible solution. It’s a bit of a hack but works better than nothing if you really want the second monitor (let me know if anyone has a better hack pls).
With OBS (streaming software) you can easily show different regions of a screen on another screen, so if you just duplicate tiny windows of what you would want on the other monitor, and then just blow up that region on your second screen, you can get more references of what you are currently drawing on your second monitor without taking up that much real estate in the main window.
Second monitor on the left:
To easily crop the windows in OBS hold down ALT while resizing them.