Doing that before the election (I assume your plan, if you were Putin, is to have all 225 “recommended” candidates withdraw?) is more difficult than subverting the, very optimistically, 30 that will get elected.
The candidates are known beforehand. Putin’s men do not need Navalny to tell them whether there is a popular candidate in an electoral district. Consolidation of “protest” votes does not make someone win an election; it gives a small extra push in contested districts.
You really don't see the difference between eliminating all the candidates (and all popular candidates) and eliminating one candidate per district?
Smart Voting™ creates these popular candidates in the districts where all competitors of Putin's guy are more or less equally popular. Knowing whom they will make popular is an advantage for Putin, don't you agree?
I have a feeling you're arguing out of stubbornness. My original point was that announcing the Smart Voting lists in the last moment can be useful, I think gave some good reasons for it.
“One per district” is 225, “all popular” in contested districts is, like, maybe 70?
Smart voting does not create new popular candidates. It’s a way to concentrate the 5 % they can access (or 2 %, if badly mismanaged by publishing the list too late) in an efficient way.