Meridian (az = 180 or 0) measurements have a number of planning considerations:
They are most efficiently observed when the target stars are listed sequentially by ra. This allows the natural Earth rotation to bring the stars by in order.
The target stars must precede the meridian only slightly, otherwise long waits are required for the star to get to az = 180.
Stars that are close to the meridian in the early evening will be migrating westward, so they need to be caught (observed), otherwise one must wait a good fraction of a year to catch them on the meridian again.
Stars with a dec greater than the observer's latitude cross the meridian north of the zenith and thus may require a long az slew because the az of the 'north' meridian is zero. This means that it sometimes smart to observe meridian altitudes in 'southerly only' or 'northerly only' groups to reduce slewing.
Stars with decs near the observer's latitude must be avoided because of the 'zenith hole' problem.
Stars near the meridian are moving very slowly in altitude. They have zero altitude velocity at the meridian. Because of my coarse encoder resolution, I could not measure any altitude difference within a degree of the meridian. Explicitly; the altitude of a star at az = 179, 180, or 181 degrees appeared to have the same altitude encoder reading.
A software reticle that clearly defines the FOV center is of great use in meridian measures.