Excuse me, please, are you living here? Do you really think there is a possibility the majority (or even 10%) of voters will vote digitally?
It's so out of character of Russian voters, that I honestly suppose you're a Prigozhin's troll.
The turnout for elections into Moscow Parliament in 2014 was 21%. 79% of voters didn't vote which means that the government can falsify their votes in remote voting and nobody notices.
This time because of protests the turnout might be higher, like 30% or 40%. This still leaves 60% of people who won't vote and whose votes can be used for falsifications.
As someone living in a state with mail-in ballots, it still boggles my mind waiting in line for physical voting is a thing. Mail-in ballots seem to be the best of all worlds. It's easy. I have time to do the research for who I want to choose. It's all backed by USPS so it's pretty damn secure- as secure as everything else we trust in the mail.
There are certainly other failure modes. In the last Hungarian parliamentary election the ruling party got less than 50% of the votes overall but literally 99% of the postal vote. That seems rather fishy to me.
Anyway, if you have long lines, that means the people organizing your elections are not doing their job right. There need to be more polling places. Other civilized countries manage this, the US would only need to take their democracy seriously.
However, codedokode's concerns are utterly irrelevant. Vast majority of Moscow voters won't use this system, neither care whether the election is scientifically legitimate. Those who do have a presumption of guilt wrt Voting Committee (for a thousand good reasons). As a Moscow sociologist put it: "a political party with 30% support aims to get 90% in the City Duma. How would they do that? Obviously, by cheating and violence".
Thus, codedokode's concerns have no meaning inside Russia, and outside they serve only the purpose intended by the creators of all this: for foreigners to scorn imperfect system, and be relieved when they update it to something passable, for the same ultimate effect - steal the election.