Yes, when appropriate. Particularly when they are young, having regular lessons or returning to play. Members acting as markers know they are expected to tell a committee member or the pro if the player seems to have a better protentional than their score suggests.
So, you are happy adjusting handicaps based on the subjective opinion of others. Interesting. I'd be shocked if many markers even bother providing committee that additional information. I mean, it is not uncommon for a marker to remember one or 2 good shots and generalise the player by saying "they could have done much better, hit some good shots out there". Very rare they say "they were lucky, won't shoot a round that low for a long long time". So, if Committee were to take commentary from a marker, they'd probably dock every new member additional shots.
Our Committee do not have time contacting new members, and the people they know, to try and build up a story on what their golfing potential may be. They hand in 3 scores, they get a handicap. We spend enough time reviewing all the general scores that keep coming in from all members, chasing No Returned Cards, etc.
I am reluctant to make any adjustments to a players handicap, calculated by WHS, unless it appears a player is avoiding acceptable rounds, but doing very very well in competitions like match play. Furthermore, it does not matter if a player is young (potentially ageist) or having lessons, because they've ultimately handed in 3 likely recent cards (so they should take those lessons into account). Once they get a handicap, they may start having lessons. But, surely you do not expect the Committee to keep in regular contact with all members, especially new ones, just to find out they are having lessons, and if so maybe dock them a few more shots?
I seriously doubt many club committees do this. Instead, we largely rely on the WHS calculation. IF Committees do need to make further adjustments, then it essentially confirms what we have been discussing. That the WHS calculation itself is not fit for purpose for new golfers.
I wonder if England Golf will contact markers and asked for their opinions on the players ability and history when this nomad handicap scheme is in full swing?