Having the game switch from a 2 frame delay to no delay in single multiplayer can help with practicing the game on your own for locals, sometimes the extra 2 frames can rarely throw someone off in local play where it’s not necessary

This is generally incorrect. The 2f delay added to Slippi is offset by the lag reduced by using Dolphin, lag reduction codes, and a good monitor.
In other words, on a good set up, the 2f delay is actually close to 0 delay compared to a CRT + console.
