Please consider integer for both axis
I like pixels :)
To avoid un-even lines both horizontally and vertically and avoid shimmering in scrolling graphics it would be great to have integer scaling on both axis.
Integer scaling vertically is currently possible but not horizontally so sideways scrolling graphics either change shape when they move - or shimmer if Lancos2_15 scaling is used. To avoid this integer could be applied horizontally too.
It would change the aspect ratio slightly. But I suspect most users probably wouldn't notice - or at least the users would have the option of choosing between the perfect aspect ratio but shimmering graphics with a slight blur - or - slighty wrong aspect but perfect sharpness without any shimmering.
I hope you'll consider adding this.

Oh THEC64 Maxi actually has that perfect square pixel mode :)
https://youtu.be/z2GACGEucTI?t=975