I'm not so picky about what the chords are called as long as i can remember them and that they are applied consistently. i don't mind camel case, i don't mind M or m, ma/mi, whatever, it all works for me, really. what i dislike currently is that i have to write min7 and m9 but i can't write min9, which bothers me only because it seems inconsistent. it seems to me that the more options exist, the better off we'll be, especially if the variations are always consistent and dare i say predictable.
the chord list in it's current state is not exhaustive. just one example, a major seventh chord is not the same as a dominant seventh chord and therefore it's not always clear what base chord i'm dealing with in the chord reference documentation, specifically when looking at the syntax for chords that contain upper extensions. i think there's room for a more thorough audit of this and i would love to see a wider range of common (and uncommon) chord types represented in the Tidal chord list. for example, i don't think there's a lot of support for "add9" chord types currently. also, i think there should be a really easy, straightforward way to add custom chords to your chord list locally so you can have custom chords like you have custom functions or whatever.
obviously (or maybe not so obviously, actually) there are many ways to name a given chord, especially when you start to talk about certain voicings of chords containing upper extensions. a lot of this has to do with the actual physical limitations of playing chords on standard instruments like guitar or piano. we only have so many fingers so often times musicians will miss off the root or the third or whatever so they can reach a sixth, seventh, ninth, eleventh, or thirteenth. the missing notes are, in these cases, "implied". in Tidal, this is not an issue -- we explicitly define each note of a chord as if all the notes can be played, which they can. something to maybe think about as chord lists start to be mapped. a lookup table returning multiple results might be an interesting way to deal with the flexibility in how we want to call up a given chord.
one request i'd like to make (and happy to think through this and contribute somehow with a collaborator, as i'm not currently equipped technically to help code it myself), is finding some room for things like simple intervals, coming up with nice ways to pattern them, and maybe thinking of useful ways of building slash chords with them...defining an certain interval to become the bass note in a given chord. simple intervals, sometimes called double stops, are super super duper important to a lot of players and i don't know of a way currently (please correct me if i'm wrong!!!) to easily move intervals around (root + sixth, root + third, etc.).
i will say that i'm generally very happy with the various results i'm able to come up with currently, finding cool workarounds to create friction with intervals, hacking slash chords, but just in my own naive way. when i started experimenting with harmony in Tidal, i realized i had A LOT to learn about music theory so it's been a work in progress for me over the last few years. the more i'm learning about theory, the more i'm looking for insane ways to exploit this in Tidal that isn't just cobbled together.