For people to use banking applications, the country needs good internet. You probably have not been to Russia, but even in the western part to the Urals there are a lot of places where there is no Internet, and in Siberia in many places there is not even a mobile connection. This requires huge investments, so as a maximum CBDC can be launched in large cities at the beginning.
So how do they get around this problem? If they want to cover the entire vast Russian territory, they need to spend huge amounts of money to create a suitable infrastructure for using CBDC, and this may take many years.
During this period, will there be two financial systems, one digital and the other monetary?
Also, in those remote areas, people are not accustomed to using the Internet and mobile phones. How will the state be able to convert them to the digital system when they are not familiar with this type of technology?
More than anything, before they delve into fullscale CDBC operations, they should focus more on buiding the technological infrastructure for internet service provision for those interiors without it and also a major case of sensitisation should be considered as many people are used to the regular financial system, mostly, the elderly folks who have spent their entire lives in the conventional financial system.
Russia can achieve whatever it wants to achieve steming from their degree of influence and commtiments to their involvements. I don't consider these few observations much of an implementation problem for them.