Yes, your right. BeatMaker does seem to have timing issues.
Meteor, however, has rock solid MIDI Clock Sync. It has latency adjustment too (both positive and negative) but you don’t need it when used with BassLine or MoDrum. It’s tight. I guess they put it their so that you can adjust the timing to deal with other apps that haven’t quite nailed it.
Just because many developers have struggled to get it working right (mainly due to the poor documentation available) doesn’t mean that it’s not possible. I’m sure Steinberg must have the know-how to do a good job as they’ve worked with Core MIDI for many years.