What a fun idea. :)
Favourite details: I like that, contrasting the Jenga system of resolution, this tower is expected to fall regularly. I also like that players have agency over how ambitious to be! A little strategy and risk management on top of pure stacking makes for a much more well-rounded system than there would be otherwise.
Would be nice to have: Some clarification on d4s would be great! How could anything be stacked on a d4?! Hahaha. Maybe I'm just not very talented, lol.