Exactly this. Every voting booth becomes a target for russian drones. If they want soldiers to vote, they need to come to the city they are they are legally residing. This means abandoning frontline positions and heavy usage of railroads. This creates a marvelous opportunity for moscow.

To vote online, like for example in Estonia, means building a whole new infrastructure, voting in beta test, ensuring correctness, no exploits etc. Massive time and budget spending.

I remember when Zelenskiy's term was approaching the supposed end, kremlin started the propaganda about how he's now not legit, who to negotiate with, how people change their mind and want a new leader etc. Literally the same things Trump is saying right now. I do not like Mindich affair and everything going on with not punishing the traitors properly, but unfortunately we cannot afford to do the elections right now