Confused about the video scaling options (particularly 4:3)

[Odjn Ryu]

OK I looked at 720p, 1080p, and 1440p video options in the Steam version to try to understand how they scale the native 256x224 native SNES/SFC resolution (8:7 aspect ratio) and I can't figure out what they're doing in the 4:3 mode, but they're not multiplying any integer scale by 4/3 so I'm a little puzzled!

Ideally (IMO) you'd want to do an integer scale on the vertical and horizontal and then multiply the horizontal resolution by 8/7 (1.142857142857143) and apply a bilinear or bicubic filter to that stretch to achieve a look that matches what the game would've looked like on a CRT, but that's not what's being done here.

Of course, there are other opinions on what the horizontal stretch should be. Some say the horizontal should be multiplied by 4/3 (1.333333333333333) but there are arguments that multiplying 8/7 is more "accurate". There's another claim that multiplying the horizontal by 112.75% (1.1275) makes sense based on a special calculation. But none of these seem to apply here.

720p
2X: 512 x 448 - This is a 2X scale of 256x224. Accurately named if you're playing the game in 720p. (8:7)

Full: 768 x 672 - This is a 3X integer scale of 256x224 (8:7). Not sure what they mean by "Full".

4:3: 876 x 720 - I have no idea what math is being done here, other than making the top-to-bottom fit the vertical. Does anyone know??

1080p
2X: 768 x 672 - This is actually a 3X integer scale of 256x224 (8:7)
Full: 1024 x 896 - This is a 4X integer scale of 256x224 (8:7)
4:3: 1314 x 1080 - I have no idea what math is being done here.

1440p
2X: 1280 x 1120 - This is actually a 5X integer scale of 256x224
Full: 1536x1344 - This is 6X integer scale of 256x224 (8:7)
4:3: 1752 x 1440 - I have no idea what math is being done here.

1080p screenshots shared below. Normally I turn borders OFF but it's easier to see the SNES/SFC screen real estate with the white border on.

2X (1080p): https://i.imgur.com/kLhMNK6.png
Full (1080p): https://i.imgur.com/FgWSwWO.png
4:3: https://i.imgur.com/DM16Oh9.png