That's up to the pilot. We are required to disconnect no later than 50' below the published minimums decent altitude (MDA) but the Stadium Visual Rwy 29 does not have published MDA so the 500' restriction applies without a published MDA or DA which would be approximately the western side of the railway bridge.

The 737 does a very good job of flying the RNAV visual approach so I tend to leave the A/P on longer. Allows me to devote more attention to looking outside and monitoring the flight patch and descent. I'll usually disengage just before, or just after, the final turn to final.

Sometimes the tower asks us to adjust our approach to maintain the separation and runway timing. For other than airspeed adjustments, that will have to be done manually.

Another RNAV approach that we often do is the RNAV X Rwy 31 - INDUSTRY at LGA. It has an MDA of 1260' which required us to disconnect by 1210', or approximately 1203' above touchdown. This means that the majority of the long left turn (from 089 track to 314 track), to line up with the runway, is hand flown.