Russian leather strops

I acquired a Russian leather dubl duck no. 53 strop that I have been attempting to restore. With some advice from very nice and knowledgeable members of this community I have managed to get the leather much more flexible than it was, however, it seems that the strop will never have the flexibility of, for example, a kanayama strop.

Is this the product of the Russian leather? I have never used or handled a Russian leather strop or one with the diamond pattern on the back. Are these strops naturally "harder" or less flexible than other types of strops? I am certainly able to bend it, but the strop just seems much stiffer than others I have. Is this the norm with Russian strops with the diamond pattern backing?

It would seem the diamond pattern on back would be to make the strop more flexible?
One thing I have noted is that all strops are different in some way.
If one has dried-out, it will take a LONG time to rehydrate it. Patience!
It is not necessary for one to be as limber or flexible as another, IMO.
Use it and hand-rub it. Only thing to do! ;)