I’m glad you came up with a solution and the kinesiology tape is working! I sometimes had kinesiology tape on my back (applied by a physiotherapist), but I have no recollection of whether it is sticky or not. Does it leave any residue on the strings? I suppose not.
I agree your drawing is amazing! It also illustrates the problem very well!
I have hypermobility too, and sometimes have subluxated a shoulder while putting on socks, and a finger while washing my hair
It used to be worse when I was a child (hurt myself almost every time at PE classes, especially playing volleyball). With time my muscles became very tense to stabilise my joints.
Finger rolls can be a problem to me, depending on the finger, and depending on how often I do it. The index and middle finger are OK for it, as long as I don’t do it too often, because otherwise, if the joint starts to hurt, it might take weeks for the pain to go away. I often stack the pinky + ring finger instead of finger rolling.
I have a different kind of problem with my pinky, only when playing something repetitive on the same frets, and going up and down the frets (like, pinky on the 5th fret and index on 3rd, starting with the index on the G of the E string, then pinky on the D of the A string, index on the F of the D string, pinky on the C of the G string, and then coming back). If I keep playing a song for too long on the same frets but just changing strings, soon the third joint of the pinky (the joint between the finger and the palm) starts hurting. I don’t know why this joint hurts. I’m not sure I’m doing any wrong movement.
Maybe I’ll try filming that hand while playing to see how the joint moves.
My biggest problem playing was with my right hand’s thumb, when anchoring it on the pickup, and putting too much weight on it while playing a Billy Idol song with fast chugging. The joints closer to the tip of both my thumbs bend backwards much more than they should, so anchoring the thumb while putting pressure on it was a problem. My thumb was hurting for weeks. I started to pluck with a floating thumb when chugging on the E string. Lately I can rest my thumb on the pickup, but I have to be aware not to place the weight of my hand on it.
Hypermobility sucks. In my case, I have a lot of muscle tension on my whole body. It sounds like a paradox, but being hypermobile in my case means I’m not very flexible. I have to do stretching regularly (and carefully) but it doesn’t help much.
Let us know how it goes with the tape! I hope it helps!