IMO, Monk should be an Expert class. Its niche is - and always was, imo, - as an expert in stunning and providing opportunities for the party, hit-and-runners, status-appliers. They should reapply stuns at less cost or be even more elusive.
Suggestions for this overgrown doc:

Make it an easy-to-read user-friendly class, not a 14-paged blanket, please and thank you.

5 features at 2nd level, 2 more from 5 bullet list at 3rd? Too much to handle for a new player who would like to play a monk. (Attention, here I only count features fron 2nd to 3rd level.) Bards generally have 4 (JAT, SoR, College and Expertise), Fighters 2 (Action surge and Martial archetype), Paladins 5 (Smite, Fighting style, Spellcasting rules, Oath and Health benefits) - and that's a max in all classes available for now, usual amounts floats between 2 and 4. My opinion: leave less toys and make them better.

Another question about Yin Yang Stance. General rule is to not add additional reactions to a player class, bc it will basically overpower any class that has reaction-based stuff easily (example: Wizard with two counterspells or a counterspell and a Shield, Rouge with two Uncanny dodges). How many playtests were there with this particular thing active in total? Can you share your experience in playtesting this thing before uploading? How many sessions were played and what results were achieved?

Thanks a bunch!