Hi,
This is not the place to complain about SB but I've been very disappointed since I bought my MX+, the source of frustration comes from their support and snob attitude. They don't care much about interoperability of their equipment so even if you decide to implement the syncless centering there is no warranty that your implementation will work with future releases of SB software.
To me is clear that an ASCOM compliant mount should work with your current approach. I see some benefits from avoiding syncs, specially for mounts that run complex sky models.
Instead of pointing fingers, I think you need to decide if you are going to support Paramounts (theSkyX controlled mounts), the same way you do with Sbig and QSI (non ascom cameras). A good way to decide is with your current user base along with the feature request poll.
Cheers,
Jose