This makes some sense, however, it implies you are forced to run the ghost at a lower setting. This means that the faster computer will still have a faster ghostas there is a very slim chance that they also slowed down their ghost by the same amount so the goal of making the ghosts the same speed and fair has not been solved

With this feature, just double tap B instead, to reset the ghost faster.

it was never a question of being fair and tbh every user has there preferred settings some might like a faster ghost some might prefer slower it wouldnt be bias to either player really as its just a preview of there current turn aslong as the other player doesn't do anything

Maybe how many frames the ghost runs for would be a better idea. Set it so it fades out at 10 frames or 100 frames.

To make it simpler, just add a button for a slow ghost, not adjustable ghost speed.
The only reason I see for this to be added is not being able to tell what happens during a fast move, so there's no need to have further options.
Doesn't seem important enough to be spent time on though. Not supported.

I would find this useful. When I'm making a replay, its annoying sometimes when I'm making a hit and I can't tell what exactly the ghost is doing. So I have to resort to trial and error to get the hit to land the way I want it to. Having a slower-moving ghost would make this take decently less time. That is, if the ghost isn't totally lying to me about what's going to happen next (which does happen on occasion).

I support this

I don't see how you couldn't just tap B every time you want to see it. it avoids adding a whole feature when you can just reset the ghost's state to see it again. In SP, I guess the speed would be useful in some ways, such as being able to see what would effect the Tori faster. Though, in MP you only have 15 Reaction-time commonly, so it would sort of be counter-productive when you're trying to see a slow ghost and then you don't really get in what you want in time.

No decision.