Original resolution on the left, 4x resolution on the right.
Reddit user DerKoun has posted their mod of bsnes which allows for mode 7 internal resolution increases up to 4 times their original resolution. Mode 7, for those who don't know, is background layer mode which allows the layer to be scaled and rotated on a scanline-by-scanline basis to achieve a faux 3D effect. This is notably used in games like Super Mario Kart and F-Zero among many other titles.
Another Reddit user, jediyoshi, also made a side-by-side comparison video of Pilotwings running in its native resolution and increased resolution.
A link to this mod of bsnes and its source can be found in the attachment below.