Do yourself a favor and get some two or three inch shims. Next time, put the queen cage above or below the inner cover. (On top of the frames) This eliminates placing queen cages between frames, messing up your comb, and not being able to check the cage without opening up the frames.
You can do a simple finger test after 48-72 hours. It's simple....pick up the queen cage and move the bees off the screen with your finger. If the bees move easily, and you can see the queen running around all excited, she is probably accepted. But if the bees have a death grip on the screen and are covering the screen (sometimes like a small golf ball like sized clump) and will not let go of the screen, they are not taking her. For the most part, most hives during a flow, will take a new queen very easily, many times even with a virgin. This does not mean they will not kill each other. It just means without the pheromones of a laying queen, some hives will allow two queens. While others may not. I have had many queens accepted, then quickly disappeared a week or two later.
I don't find Russians hard to introduce. Unless you have a hive that is not ready to accept a new queen. There is at least one study (I think published last year in one of the bee mags) that had shown no difference in Russian queen introductions as compared to other queen being introduced. Look at it this way...if you are introducing an Italian queen into a previously Italian queened hive, and have problems...nobody says "It's because you were introducing an Italian queen". But the moment one is introducing a Russian queen into a previously queened Italian hive, and you have problems, it always assumed "Hey, it's because you were requeening with a Russian".
One of the things I have found out, is that later summer requeening of packages, and for many that means upgrading their queen to other stock more readily available like Russians and Carni stock, is that queens are harder (Or simply may take a couple days longer in the cage) due to the flow ending, etc. It just seems later in the summer, everything from queen rearing, queen introductions, etc., become harder and harder. Many times, this is when beekeepers are requeening packages, and then it's just reasonable to blame the queen type.
One last advice....always remember, you have about 10-12 days after the last of the brood is uncapped before you start developing laying workers.