Hi @Jin Liu
That's interesting, thanks for sharing your thoughts and research on this. What I tend to do is when I consider my elbows locked and the position feels solid I don't try to force the rto 'more than necessary' and expend more energy that seems to be required. If my elbows are indeed microbent maybe I would benefit from replacing part of the dips (which aren't a problem) with extended all-out rto holds (10 s or so?) to see if I notice the difference that you mentioned. I'd be interested to hear from a coach e.g. @Alessandro Mainente, whether this training plan makes sense.