As far as I can see, my DAW (Reaper 5.18) uses system events for synchronization (setting on "native events").
But I always thought that this should only affect synchronization to external hardware, not synchronization of one plugin to another, or to the host itself.
I am having a project in which I run one instance of Arturia Spark, one instance of the Jupiter8V with arpeggiator and the APR2600v. While Spark, Jupiter and the system metronome stay in sync, it seems that the 2600v is slightly getting out of sync over time. It is only slightly, so it is actually hard to tell whether it is running ahead or falling behind, but after some minutes of 'free running'. the whole timing starts to sound a bit sloppy.