Yes. This is a long-known phenomenon.
I was able to get improvements in Pebbles based on the idea of forgetting
unsuccessful results. It has to be done somewhat carefully, because results
propagate up the tree. But you can definitely make it work.
I recall a paper published on this
I've been using Leela 0.10.0 for analysis quite often, and I've noticed
something that might lead to an improvement for the search, and maybe also
for other MCTS programs.
Sometimes, after putting hundreds of thousands of simulations into a few
possible moves, Leela will appear to favor one,
