There are a few other folks on here more into the scientific end of beekeeping and call tell you how many generations the genetics of the Russian would pass down and be of benefit in your yard.
I know for a fact some Russian breeders open mate their queens and are in the Russian bee program. So how huge an area would you have to have isolated to actually have a russian queen. How far does the DCA extend. Several mile radius but maybe closer to 1 or 1 1/2? I'm have no idea but large. So from the get go if your queen is not an artificial insemination from pure start you are behind the eight ball from the beginning.
Then when your new queen mates in your yard? How much land do you own. Well I can't see the queen being considered Russian long. But how long to the traits carry down as in varroa resistance etc. If it gives some resistance in your bees then it is worth it. I will admit I have bought a few that a queen producer calls Russian hybrids. At least this is up front on what you are getting.
The original USDA program i think was isolated on an island in La. Not sure but I am sure others will pick up on this thread and correct me in my errs
I am not slamming the program. If they are certified Russian Breeders they hold strict standards. They have a set number of lines they have color coded to reference. Each breeder gets bees from a certain color code to maintain. Then they swap the lines between each other to keep up with the lines and diversity.
Here is a well know Russian breeders web page. Read his recommendations on keeping Russian yards separate from others:http://www.revisrussians.com/
Stick with local proven queens if you can.
About the Russian queens. I may be confused so help me out. When you buy a Russian queen from a Russian breeder she should be 100% Russian. The breeder used an artificially inseminated queen to produce an egg which turned into a larva which was grafted into a queen cell and emerged as a queen with Russian genetics only because her mother was Russian and her daddy was Russian. Now she open mates with whoever and then her daughters are hybrids unless the queen that open mated did so with a Russian drone. So maybe I'm wrong but you start out with a Russian queen not a hybrid.
The other thing I'm confused about is. Why after a few generation you no longer have Russian genetics but after a few generation you still have Italians and Carnis in an area where there are Russian drones Italian drones Carnis drones and feral drones. Do Italians and Carnis trump Russian and feral genetics?