good find. this will be fixed with upcoming 2021.4 RC3
re virtualcams (OBS, spout) i’d argue this is lower priority because as i understand OBS can now send spout directly. so it would anyway better to go via spout directly instead of virtualcams.
the reason why those and the ps3 are not working here, is that those are using the old windows video api (directshow) and thus are not compatible with the new mediafoundation api.
if need be though it should be rather straight fwd for any developer to add a directshow-based videoin node. it could either be added to VL.OpenCV, which i think has all libs in place already and/or become a separate VL.Video.DirectShow lib based on e.g. DirectShowLib