I was going to post this in the temperament thread, but it a bit specific. My lure to other temperaments is different “tone color” in different keys. I ideally, I’d have squiggly frets all over the place to have one key “perfect” and let the other keys be “off”. But that’s not practical for a DIYer. Adjustable single string frets aren’t either. (I need to find that link) So, the idea is to tune the guitar in all Major 3rds (M3) and have frets that come close to JI. Then, assuming I play across more than up/down each position will have its own temperament. But, will this be playable? In first position, the 5th two stings up would be a JI M3+m3. Is that a playable 5th? Playing in 5th position, across strings, I’d stiil have a JI M3, but the M3 on the same string would be the difference between a JI P4 and JI M6. It seems like there’s potential, but depending on how different the intervals are, this could be a hot mess.