If you pausing on a short activity maybe, but going from say 150 to 100 in what's effectively 1s in data points and then it climbing back up has little to no impact.
I did once with a slower rider, I had pauses for 1h15m over a 4 hour ET. 1 of which included a coffee break, did not drop my avg by even 1bpm, it actually want up as after the coffee break I went out solo.
It will very much depend on what your doing as to how much or how little impact the pause will have.
There is even a known hack with the garmin chest straps, may work on other, you start recording, get up to your 80%, take it off and stop recording after 30 minutes, your avg won't change at all. It does snot factor no readings into the calc. You could do jump rope for like 2 or 3 minutes, drink beer for the rest and still get 300 points.
Finally synced, speed data only. So only 100 points instead of 300. Just as well my shoe booster is done, because I'm not going to be hitting 900 points weekly any more. Discovery hasn't responded to any of my logged queries, nor on Twitter.
I am using Movescount. My workouts look like they are syncing according to the timestamp on the app but I haven't gotten any points. Even Samsung Health syncing is patchy. Discovery devs are not looking good right now.