Before I forget, @
Spinosaurus mentioned Doc's Fireball. I do feel the need to talk about this.
The IASA is legit garbage. It's not really an issue on Mario, he has the mobility to cover the IASA window pretty handily, but if we look at the old IASA (going by Brawl, I believe it was 43) compared to what it is now, which is 53, that's insane!
It's been in my head for a while but if Doc Pill had the old IASA the character would be ridiculously better. Think of the first custom move people bring up when they talk about optimal Doc customs, it's usually fast pill, all for the sole reason of space control. Vitamins have a really good trajectory in this game, the arc is basically perfect for stopping momentum to some degree.
If this had an actual plausible IASA (maybe 43 would be excessive, but like, I have no other number to pull out) they'd actually be very usable for space control and would help tremendously. In fact, compared to the bunch of other changes you'd need to make to have him be a lot better with the current pill, this would probably be like, the quickest fix possible.