mrflib could you list here (for thread completeness) what functionality is missing?
I am not using Asiair, I am controlling the mount via ascom.
What I am missing:
On both sides of the meridian a zone can be defined by the user (up to 30 degrees), inside which the user has the choice to put the scope into the orientation he likes; also - in case of gotos - (platesolving and sync is a goto, too) the user has the option to prevent the mount from changing the actual orientation of the scope, i.e. if the scope is in the "wrong" orientation, no flip is performed.
But: a flip can be done, if and as soon as the user likes to (that needs a button or command: "Flip now").
In short: the photographer himself has the freedom to decide whether the mount will flip or not, inside the limits of the defined zone. Inside this zone the default behaviour for the mount should be: remain in the state (orientation) you are.
These limits should be set by the user according to his setup, so that he can manage everything without the scope colliding with the tripod or the mount.
If a user does not want to take a risc (or he cannot calculate it), he can set those limits to 5 degrees for example , so he can finish a running exposure past the meridian for about 20 minutes and flip then.
If his setup permits, he can set those limits much larger and has more freedom.
The rule should be: give options to the photographer, not restrictions!
A meridian flip is something I mostly would like to avoid, if possible and reasonable.
Now to the example I gave above:
If the target at the beginning of the session is located - let's say - 1.5 hours before the meridian, I could slew the mount from the western part of the sky to the object, and if the options I explained above are existing and the limits are set to 25 degrees, the mount will slew to the object without flipping, remain in the "wrong" (western sky) position even when I platesolve and sync, and track towards the meridian, which it will reach nearly 1.5 hours later, cross it (from now on in the "correct" orientation) and continue tracking for the rest of the night, until the target is too close to the horizon for imaging.
This would mean an imaging night without a flip, I have all subexposures oriented the same way, I do not have to readjust guiding, I do not have to platsolve and sync after a flip, and I do not have to deal with several other difficulties that can occur when I control the mount from third party programmes via the ascom driver, difficulties, that are described on the net.
I have been doing astrophotography for many years and still remember high end mount controllers that did not put ANY restriction on the user. Meanwhile the design of mount controllers has changed, but even today reasonable freedoms and options for the user inside a certain zone on both sides of the meridian can make for easier and simpler workflows. Of course they also give some responsibility to the user to prevent the scope from colliding somewhere. If this responsibility is not welcome or suitable to a user, he simply may refrain from using the options regarding meridian handling and use the mount in the default state: stopping short after the meridian.
The described options (or similiar ones) are present for example in EQMOD, GreenSwampServer (both for mounts of another manufacturer) and the controller for 10 micron mounts; there may be others that I do not know.
Matt