Last night I went beacon hunting on 23cm with my tiny indoor 2 element beam. I monitored GB3DUN on Dunstable Downs for several minutes. This is probably my best chance of copying a 23cm beacon.
Just occasionally there was a very brief signal that may have been this beacon. It was there for (at most) a second, then was gone. The direct path is very obstructed and my only real hope is by aircraft scatter. The impression I got was this was not aircraft. I have no idea if you get MS on 23cm.
Other beacons I also looked out for on my waterfall, but nothing was seen.