The stiff ring is universal with these (I noted it on my review as well, a coaster makes adjustment easier if you change mag regularly)the adjusting ring is stiff but moves smoothly,
The 56mm front lens means I need high mounts, with some clearance available If I removed the front flip up I might be able to go as low as med'.
Removing the flip up gives you 4 or 5mm extra, it's a bit thick
As you conclude, a good VFM scope.