A similar question has also been asked in the Venu forum.
According to an earlier post by Garmin-AmberD, the 5.60 firmware contains the changes from 5.10 to 5.30 and 5.30 to 5.60. The change log for 5.30 states that support was added for calibrating the elevation from Garmin Connect Mobile and I have been looking forward to this functionality, to improve the elevation accuracy and stability on my vivoactive 4.
Today my watch updated to version 5.60.
I've checked the Garmin Connect app version 4.39 (updated on Feb 3, 2021) on Android 11, but could not find the option to calibrate elevation. Can someone please point me to where this functionality can be used?