Can confirm. I live along the line and it is atrocious in both waiting times, and in the case of Woodhaven to 71 Av, speed. There had been times where I just have to take Q10, and then the or the , just to get into Jamaica.
Also another thing I've found about the proposal, and it's just a nitpick but still, is that 123rd St and 125th St are set to be removed, yet 124th St isn't, and I always see that stop deserted as hell.
It would be cool to see it get the proposed Limited service though. As a kid, after the Q58 got it, I was always wishing for a Q54 Limited. Now that I see how bad the service has gotten in speed and waiting times, I think it's time to give it some Limited service.