Long been my biggest deterrent from trying out Mac, and even moreso me feeling Sakurai mainly built the take on him in SSB4 solely from his Brawl Assist Trophy-counterpart, right down to being a "gruff boxer. Which reminds me, he's a bit too grump in Smash (why no joyful celebration like in both NES and Wii upon victory?)
At least Hewdraw Remix allowed him bit more interesting leniency in a way you talked about - this time aerials allowing better setups to grounded attacks and then some.
On that end about Punchout, I've long been baffled by how inexplicably generic the presentation of the series has been, even moreso in Ultimate than in SSB4 - which is mainly due none of the other boxers from the series being featured anywhere (not even as an Assist Trophy?), complementing sadly with how Mac's level can be also be turned to a more generic "Smash Bros-verse" boxing ring.
Combined with my above feelings on Mac, it makes the current representation of Punchout feel incredibly lacking and disconnected from the known main draws of the series - arguably the boxers themselves you take on as the little guy and just the oozing personality from EVERYONE involved in the series. Smash not bringing much of this has made me not really be invested on the series there as much as I am outside of it. Kinda of a shame as I remember championing for Mac some bit on the side during SSB4's speculation era.
Also Doc Louis not getting any pep talk sessions on fighters... what a missed opportunity.
(It wouldn't have been that hard, especially if it's just one guy talking briefly!)