Since MikroTik doesn't seem to be interested in giving us this information, I thought I'd start a tracker.
As of 2/14/21, the most recent SwOS release is swos-css610g-2.13rc25.bin, from this post:
viewtopic.php?f=17&t=167891&p=842835&hilit=rc25#p842835
Please update as new releases are provided.
-MB