I'm wondering if there is a way to play POP: Two Thrones at 1280x1024. I used a fix for Sands of Time and Warrior Within, but I can't find anything on this one.
Not sure if it is supported by PoP:TT but some games let you edit the config file manually to get the resolution that you want/need. Might be worth a try
You could try the black bars / pillar boxing approach. (For my setup at least) using nvidia's control panel turning off LCD scaling runs it non-squished / stretched but obviously smaller since it isn't scaled. My native resolution is 1280x1024 too