Yes, or anywhere in between.
The technical reason for this is, that Ardour splits the plugin’s process-cycle at automation points. This is done in order to reach the value of every given automation-point (and not average it away).
For example: Instead of normally
synthesize (duration = 1024 audio samples), Ardour does
- synthesize 123 samples
- change automated parameter, inform plugin about parameter change
- synthesize remaining 901 samples
However, for VST plugins, Ardour sends all MIDI events for the complete cycle (here 1024 audio samples) to the plugin. This can result in lost or duplicate events. Also some plugins cannot cope with smaller cycles. A fix and a workaround for this already in place in Ardour/git.