Well, then it’s hardly a difficult choice at all, is it? Users who would like to force everything to 640×480 still can do so, and every one else has automatic scaling to the displays native resolution. Whats not to like?
Question : what happens if you use a smaller (resolution – wise) display? We’ve seen some portable builds on the site, those often use displays with limited resolution.
On first glance, the proposed change is still an improvement, but I’m not an expert.
Another side effect to consider: If you use a single installation of RetroPie on multiple displays, performance might vary, depending if you have a SD or UHD monitor, right?