annoying data timestamp lag when flushes are skipped

[Dieterbe]

we use ticker based loops in which we increment timestamps and call output Flush methods. if a loop iteration takes too long (due to an output's Flush taking too long for example), ticks will be missed and the timestamps in the data will start lagging behind. this can look like data is ingested with a big lag, but it's just that it's realtime, just with timestamps that lag behind real time more and more.
really annoying.

we can probably fix this as part of #1