I appreciate your frustration, Mark. As Daniel has mentioned many times before, we do have to take some difficult decisions about where to focus our time, and we do try to ensure that the widest range of customers get the best bang for their buck. Having said that, we do also spend considerable time looking at problems such as this that do only affect a handful of users. We do have some instrumentation code in Dorico already, but it currently doesn’t contain enough specific information to diagnose this particular problem. I do hope to spend some time adding a bit more instrumentation that could help.
One extra bit of information that could be relevant: does this happen in page view as well as galley view?