Literally all the Tier 7 and even most Tier 6 stuff is just a casual body movement calculation; if a character splits a planet in half by swinging a sword, and the KE of said swordsman's body movement gets a Tier 7 result, the planet splitting feat is the part that takes priority. If Tier 7 stuff is just casual body movements, that's horrible reasons for Tier 4 stuff being outliers. And Tier 4 comes from a bunch of in depth lore feats. Our policy on outliers has less to do with number of feats within specific tiers and more to do with specific context of each high end vs low end portrayals. It's possible for a character to jump from Tier 9 based on hundreds of feats to Tier 2 based on one feat and still be consistent on Tier 2. If the character is either a Saitama protagonist who just solos his own verse, his best feat is consistent. Or for RPG protagonists where tier jumps being massively absurd. Going from struggling to fight street thugs to basically going toe to toe with terrestrial to Cosmic gods via training, grinding, equipment trade, learning new techniques is the basic story of every RPG protagonist. Likewise, a 4-B character could have multiple 4-A feats and still all be outliers if the context is more or less just plot armor of "Chip damage that caused minor distractions" or "He was effortlessly stomped, but still survived barely.
Listing the number of Tier 7, 6, or 8 feats compared to listing the number of Tier 4 feats is a terrible practice. Almost every long running character in fiction has far more low end feats than they do high end feats. Whether it be lack of destruction is via ki control, or it's just the writers don't care about making their protagonists look as strong as they should be for the sake of advancing the plot or giving a conflict. Just because a character's "most Frequent portrayal" is "Faster than a speeding bullet and more powerful than a locomotive" is not an excuse to call all their various FTL feats, Massively FTL feats, planetary feats, and stellar feats outliers due to be far less frequent than all their Tier 9 to Tier 8 and Supersonic feats. Frequency and Consistency are two different things, using the quantative number of feats for everything is frequency, but consistency uses context. Having several Tier 4 feats that are otherwise consistent with the lore should almost never be considered outliers. Also calculations for spammable techniques in their pure forms are bench marks. Just because a technique was calculated at X Tier, that means nothing beyond they can't be any lower than that, they could be much higher if they have techniques with higher calcs and/or feats that are far superior. The Bye Bye Cannon and Giant Bowser's punch is just casual body movements; the former is High 7-C and the latter is High 6-C. It just means anything lower than High 6-C is blatant downplay. And leaves 6-B, High 6-A, Tier 5, High 4-C, or 3-C stuff uncontradicted yet.
Anyway, it appears Dino has not commented yet, and there have been a lot of posts. But it's explained in the OP why Kamek's magic is consistent, he casually transforms fodder enemies into boss enemies on a regular basis, thus making is magical influence on par with Power Stars. And his magic bolts inherently take more effort than his transformation spells, so his magic bolts are inherently superiors. Furthermore, even if that wasn't the case, Baby Bowser is still much stronger than Rapheal the Raven. The Raven was a fodder enemy before Kamek, but became a boss afterward. Bowser is the boss before and after Kamek's amp. With him being the final boss with it. Yet Yoshi defeated Bowser with the amp and thus should be a lot stronger than the Rapheal constellation feat. Also, gag feats are often prone to outliers normally if it's a one time thing far above every other feat. Prime example is Simba's Moon level feat. But if they have multiple gag feats, toon force being explained, or consistent with lore feats, it's not an outlier. The Raven feat is far from Mario's best feat, and is thus consistent with Luma and Power Star feats.
Also, the Power Star uses the same universal energy source to close the black hole as they do to amp their users or do the "Go boom and a galaxy is formed". Also, black hole feats in fiction are unquantifiable as far was swimming in black holes are concerned; as they'd be High 3-A durability feats otherwise. But creating black holes and closing black holes are quantifiable. And if they used the same universal power source as physical amps, it can scale. And it was already linked above that there are animated showings as well as some notes that Hawking's articles actually did inspire the showings of black holes in the galaxy games. I know the last thing Dino said is that "She should have waited," but I think he's about to offer more details for why High 4-C to 3-C is consistent.