I had already posed this question as a reply to the very interesting update by Mark Stock https://discourse.radiance-online.org/t/talk-a-decade-of-radiance-tricks/2712 but I thought it would have needed a post of its own.
In the slides by Mark Stock one reads that -u+ to could be used to remove noise and from the description of RPICT that this option would turn off Monte Carlo sampling. Would this be correct? Does this carry specific cons when used? When one should decide to use this option to reduce noise?
Thank you for your help!