I agree entirely on the madness of doing a sync just before the mount does a pier flip. It achieves nothing and, because the mount is in an anomalous state, has caused all sorts of problems.
The ASCOM contract is as I said “Do it correctly or raise an exception”. This contract should be honoured by all parties - the driver, the application and ASCOM itself.
My post in 2015 did not say that silently doing nothing was acceptable in all circumstances, only that I thought it was the “least worst” option for the specific case where the mount had tracked past the meridian. Really it’s making EQMOD non ASCOM compliant because SGP is not ASCOM compliant. Two wrongs don’t make a right.
I was not suggesting that it was acceptable for the general case where a sync is not possible.
With hindsight it was a mistake. It would have been better for the problem with SGP to be fixed. It isn’t difficult, and in the case of a sync before a meridian flip the exception can simply be discarded.
In the case of the different problem that this thread raises silently ignoring a sync is, I believe, definitely wrong. A sync in the context of doing an alignment from cold is a major change to the mount functionality, in this case changing the mount position by 120 degrees.
Sync is intended to make minor changes to an aligned mount’s pointing model, not to do an alignment from a random position.
So I would suggest reinstating the error in EQMOD. SGP should be trapping and handling the error. It may be that the pre flip sync has been removed. It was causing all sorts of problems with multiple mounts.