Hori made SNES/SFC controllers ostensibly for fighting games with the L and R buttons on the main pad versus the top left and right corners. Without considering the turbo ability, can you play faster with that change?
Not limited to SNES, plenty of USB adapters that work with SNES controllers on PC.
Edit for image: https://imgur.com/a/KpNyf5p
This is a general speedrunning question. Joysticks put shoulder buttons on the main pad and I can map a controller to Steam and launch through that if the PC game doesn't support button remapping. Hori made the HPS-07 that maps L1, L2, R1 and R2 to the main pad for PS1 and currently makes controllers that map 2 of the 4 shoulder buttons for PS3/PS4, Xbox One and Switch.
Maybe no one has an opinion and that's okay. I have a PC and Switch compatible joystick I can test for myself. Just was interested in SNES/SFC.
Turbo aside, I'm not sure how significantly faster having all the buttons on one place makes you when compared to having the L/R buttons on your fingers.
On pc, it p much has no effect since keyboard controls give you the same input style by default. Obvi turbo would ban it in most communities.