The more I play Puff the more I feel she should not be buffed quite yet for a few reasons. I think her tier-list placing is coming from a lack of Puff mains. If you just pick her up casually, you will get bodied. If you pick her up more seriously you will still get bodied. However, if you play her long enough to perfect her movement and learn her matchups, you'll start to pull things back to even or better.
Though PM's recoveries tend to be trickier to edge-guard than melee's, they are still exploitable. Ganon initially seemed difficult to edge-guard relative to his melee self due to his float and flame choke changes but now I feel just as comfortable bairing him to oblivion as I did in melee. G&W's recovery seemed impossible to deal with initially but I have gotten used to to punishing it fairly consistently (still is ridiculous though). A well timed bair is still probably the best off-stage move in the game. You just have to know exactly where to float to cover their options.
When people think of Puff they probably imagine her floating around throwing out Bairs. What many people don't realize is that Puff is MOST dangerous when crouched on the ground a couple of lengths away from her opponent. Shorthop Bairs, Fairs & Nairs come out fast and are super safe on shield when properly spaced. Most importantly they auto-cancel on short-hop (Fair didn't when shorthopping in melee but does in PM if you throw it out right away)! The auto-cancel gives you so many options to continue with your pressure. A Puff that's crossing you up with aerials is difficult to hit and difficult to punish due to her insane aerial mobility and the quantity of aerials she can throw out. Since Puff is constantly auto-canceling during these mixups, you can quickly grab, use a grounded move or even rest in between aerials making it difficult for your opponent to do anything without getting punished for it.
That being said, newer Puffs are very afraid of going in, and justifiably so. Until your movement is very VERY crisp being close will be a disadvantage simply because you're so damn easy to kill. You must master her surprisingly long perfect wavedash and perfect waveland, especially the latter. Doing so will make take your punish/bait game to another level. You also need to learn when to use her god-tier crouch over shielding (read: most of the time). A whiff over a crouching puff or a CC can often lead to a stock. You need to play more like Mango than vintage HBox in PM to be successful.
Newer Puffs also do not utilize her amazing nair properly. Auto-cancelled nairs are by far the best rest setup in the game and the hardest to master. If you catch someone with a nair at the beginning or end of their jump you will likely get a rest out of it. Better yet, you can predict from the hit whether or not the rest will land, or in other words you can reliably hit confirm into rest from an aerial (yay!!!). If they're on the ground and you catch them with the last active frames of Nair you can also combo into rest but it's a very tight timing. If you catch them at certain percents with Fair (and Bair/Nair but less so) you can knock them down and jab reset into rest. Or you can land next to them after a nair and up-tilt into rest (though I tend not to because up-tilt is slow to come out).
Lastly, the better you know a matchup the tighter your punishes will be. Melee Puffs all know that a whiffed Marth grab leads to a rest. Such punishes exist in nearly every matchup. Did you know if you catch G&W at the top of his up-b you can rest him? Additionally, her CC is BETTER in PM which means more CC rest punishes. I've even CC'd Ganon's down-b into rest and that move flat-out kills Puff at 70%. As the meta develops, Puffs will uncover and begin exploiting these rest opportunities.
There are simply not enough people playing Puff. HBox has shown that she can compete and she can only get better as the meta develops. Maybe minor changes are justified but I think we should wait and see.