Not to sound overly-critical, but I do wish there were more clothing items that didn't take up the entire upper/lower body slot, and were either purely underwear, or outerwear.
Like, the first clothing items we got in the game were all like this, and while the default and Witch outfits were pretty basic in terms of design, and the Demonic underwear was literally a palette-swap of the plain underwear, even the more-complex Elven set was like this. (to clarify, I'm not against having simpler sorts of outfit variation. It was early in the game's life span, and you couldn't devote as much time, effort, or energy into making complex clothing. And, starting off slow makes sense for a game.)
The next outfit is the PJs set, and that one still made sense. Most outfits at the time (and to this day) had a tradeoff attached. More Arcane for less max HP, more Allure for less Willpower (or vice versa). But the PJs were pure upside, at least seemingly. But, the downside was secretly that it took up multiple slots, restricting your other clothing items and more importantly, making yourself easier for enemies to strip down. So that seems fair, and a cool idea, if it was the only item like that. And the PJ set hat and shoes didn't really make sense given that logic, but hey, it's an item set. You can't just have different items in a set have different effects.
But, from that point onwards, I believe that every single clothing item was exclusive, just like the Jammies. Which takes away a bit of the fun, for me at least. Cutting away about half of the customization options kinda feels like it's skirting the implicit "promise" made by making that a feature in the beginning of the game. Now, I do think that the new clothing items look a lot better than the old ones. Plus, having them take up both slots does make it easier to make them skimpier and have more intricate designs. And I'm fine with that. But, I think it would be great to get some more outfits like the Elven set that allowed for wearing panties.
And yes, I do love the Corsair set for being, at least partially, exactly what I've asked for! Especially with its unique panties. And I hope we see more like it in the future. Although, I do think that it could use a bit of tweaking. I seem to notice a bit of bias towards making affection-related outfits much more powerful than any other outfits, specifically by giving them all 0 downsides. If the Corsair shorts and panties got a downside, got their stats nerfed to +5, and/or, like I would probably prefer, the shirt got a buff (perhaps a new Skill, like the Succubus outfit has; maybe to let you Steal money from hit enemies?), I think they would be more balanced.
I don't know what to call it, personally. It feels adjacent to "power creep", but not quite. Basically, when you have all these super-cool new all-upsides event clothing pieces, and they're not unique in the multi-clothing-slot aspect since most shop clothing pieces have that too, it kinda removes any motivation to actually get the shop clothing, besides plain completionism. This is solved by the Succubus outfit having a skill to learn, which is enough intrinsic motivation.
I'm mostly looking at the New Witch outfit here. It's kinda useful? Or, at least isn't entirely outclassed, like the basic panties/skirt are upon gaining the Corsair equivalents. But, why sacrifice 10% max health, when you could get a better Arcane boost, plus a lot of Speed, from the Mystical set (that is what it's called, right?)? I mean, maybe there's a situation where squeezing that last little bit of Cooldown out matters. But if Cooldown is all you care about, then the Dancer set is right there! Personally, I think the new Witch set is better than the Dancer set, since Arcane is a useful stat to boost, especially alongside Cooldown. But the point is, that they aren't as unique anymore.
In conclusion, I think that if future added outfits were of that more modular type we used to see, it would add more of a reason to consider using them over the decidedly-stronger clothing items you get from relationship events, even if the use-case is rather niche. It'd also add more opportunity for strategizing. That outclassing by event clothes very well might be intentional on your part, giving out definitively stronger items via events to encourage the player to engage with that aspect of the game. That's a good game design decision. I don't even need you to not do that. I think making shop outfits not be multi-slot would make them a lot more interesting, gameplay-wise, even if not more powerful necessarily. And event clothing possibly being more modular would just be the icing on the cake. Yes, even if that means that they'll be less complicated, and even if that means they'll be less skimpy.
Jeez, I did not think I had this much to say about this. TL;DR- I think that, the more outfits we get, the less that the multi-slot aspect of clothing becomes an interesting and unique downside for more powerful and sometimes purely-beneficial clothing pieces, and the more it serves to limit player choice when it comes to equipment, and (in my opinion) limit the fun that one can have with the game's clothing mechanics. Thus, I think that the game experience would be improved by adding more clothing items that only take up one body slot: overwear or underwear.