This mod was pretty fun and impressively high quality, a great reason to return to hollow knight's excellent combat. The highlight is the presentation, both music & visuals are gorgeous. The boss design is awesome as well, although if you're a fair telegraph purist these fights might annoy you. It's been a while since I've played hollow knight, so I'm not sure on this, but it feels like all the bosses in this mod are designed around a slightly higher combat tempo than the vanilla bosses. This overall is part of what makes them fun fights, although it also makes them more punishing. it's easier for taking damage to lead to taking other damage and my first few fights with 2 of the bosses were awkward and overwhelming . {It was hard to even survive long enough to get my bearings on what was going on and start learning the fight}

Sidenote: Shoutout to stalwart shell, it made these fights feel a lot less frustrating.

It's also worth noting how elegantly pale court content fits into the game. You could totally install this mod for an unsuspecting first-time player's playthrough and they wouldn't notice what it's adding until they made it to godhome.

More specific thoughts
I somehow fought the bosses in descending order of diffiuclty. Hedgemol who i started with was by far the hardest, i struggled quite a bit with isma, found my groove with ze'mer without too much difficulty, and beat dryya in less than 5 tries.

Hedgemol is my least favorite one, mostly because they're so fond of doing 2 masks of damage. I also feel like the fight is designed around needing sharp shadow's extra dash length, which makes the great knights pantheon even more annoying. They're also the most like existing bosses in the game since failed champion exists. Despite the above problems, it's still a cool fight. I like their shockwave on landing attack a lot. It was satisfying to learn the points where i could sneak in extra aggression in this fight (more so than the other bosses). I also think this fight makes the fun combat potential of monarch wings shine.
Hedgemol took me so long to beat that it set some pretty strange expectations for the rest of the mod.

Isma is an awesome fight, i love how unique it is. The battle does a great job of forcing you to manage multiple different hazards while still letting you develop a reasonable rhythym. The traps that you can forgot about and the movement blocking vines are especially interesting. This fight really stands out, it feels like it has such a unqiue style (while not being gimicky in an annoying way).

Ze'mer is fun, their erratic attacks are neat. I used longnail and mark of pride here and it felt like this boss wasn't an incredible match for the tried & true pogoing plus a bit of parrying. This fight is like sly if they were not small.

The Dryya fight is simply solid. It's fast,fair and fun. A good clean nail vs nail duel that's not dependent on any tricks. She's like a much easier PV, and i consider that a positive.

I dislike the champion's call boss rush. Firstly on account of being a boss rush, which is too punishing for my tastes. Then I despise the ogrim + isma fight. They synergize with each other so well that they're actually frustrating to fight. It feels like as you dodge one, the other one will consistently dunk on you. Sometimes they're attacks come together to form something that feels unfair at my skill level. The worst part is that the solo isma fight is just better.
Oh i also wouldn't want to fight hedemol without sharp shadow, but I'm not sure I'd want to fight any of the other bosses with sharp shadow.
I'm not annoyed at dropping pale court without grinding this out though, I'm definetly a different person than the me who played godmaster

Also shoutout to bosses honorably bowing at the start of fights, especially because of the way they instantly transition to an attack that's hard to dodge if you disrepect them and attack immediately

Another shoutout to the credits area, finding that was a cool moment

The new charms are glorious, each one feels really impactful. Although the weird part is that without giving extra charm notches this power comes at the expense of other things a player would want to take for granted in their build. Getting the spell modifer one first felt like a good reason to not be annoyed that i fought hedgemol first