I use v/s all the time to REDUCE the climb rate. Even at the flight levels. Company policy is that the world comes to an end if you use v/s at altitude ("you have no speed protection!!!!). Uh, if it's being used to REDUCE climb rate how is that a problem? Using it to INCREASE climb rate is beyond dumb.
Nothing like being on the tracks and getting a climb from FL350 to FL360. VNAV, rocket power!!!, idle...., level at FL360. How about 200-300' FPM? Most folks won't even notice. If they're standing they will (level sensors in your feet). Otherwise the .5 degree pitch change will be barely noticeable.
There is no engine noise in the cockpit in cruise. Behind the wing it's very obvious.
U.S. Airman's Information Manual (AIM), has the requirements. Less than 500' FPM climb, or 1000' descent, requires notification to ATC. It's not prohibited, you just have to advise ATC. In the tracks (NATS) or non radar you're giving a time to report level. How long you take is up to you as long as you meet the report time.