if we take a step back, would you say that, besides the muddy bass, the scooped presence area coupled with the bright lower treble was your problem with the Cincotres? The treble can indeed come off too sharp if you have such an imbalance.
I didn't find the bass particularly muddy but on some tracks that were warmly mixed I found the midbass bleeded into the mids and you had the tendencies to turn up the volume (unreasonably) high to compensate. Bass didn't have much depth and room compared to what I'm used to.
It was definetily sounding colored and not neutral or studio-tuned as it was advertised..
The treble was far too bright, any sparkly ambient with lots of details from bells to hihat, percussion, choir, leads sounded so dry and so bright that you were absolutely sure the recording wasn't supposed to sound like this from listening to the same tracks on various sources and sets over many years.
In warmly mixed recordings however it was less apparent, in those cases sometimes it came off "crisp" (positive) other times it came off colored as well (too dry).
ZiiGaat Cincotres and IKKO OH10 both let me down for the similar reason.. The timbre of the treble was too dry on Cincotres and on IKKO OH10 it was simply too "tssch" (scratchy in the treble) what I'd describe as sibilant, bright to the point it distorts the sound.. Maybe it has to do with compromises in the IEM drivers that I'm not technical enough to understand.. Both of them never sounded natural in the treble, it always came off as colored too bright.
My daily driver the Ultrasone Pro 900 is kind of dull at low volume it doesn't resolve very well and the mids+treble is kind of absent, but where it shines is moderately high to high volume at that point it makes up for the lack of treble at lower volume it becomes more even at high volume - which makes it incredibly hard to beat at high volume imo (especially with dnb, techno, etc) because it doesn't distort easily even if it is not as resolving as more expensive headphones .. Which still to this day makes it my preferred headphones for EDM beating Kennerton Magni, Campfire Cascade by a mile.. Campfire Cascade is not as resolving, you just drown out everything with bass which leaves no room for resolution in the treble.. Kennerton Magni just lacked a lot of subbass to be enjoyable to listen to EDM to, music sounded too bright again, kicks landed flat and the bass lacked depth/room.