Looking at some of the recent delayed flights, where aircraft seem to have been in the right position at the right time, other explanations would be ATC complications, tech problems, ground handling complications, or unavailable / out of hours crews.
Correlating delayed flights against factors that would have affected other airlines seems to rule out ATC delays in some cases, which would leave ground handling issues unique to the BM fleet, tech problems, or crew availability problems.
So my hunch is, crewing is a contributory factor to the recent problems, and I hope they fix that before approaching any route expansion (for which they also don't seem to have sufficient frames).