I think those living in the facilities can choose wherether they want to vote on Flemish politicians, or the Bruxelles parliament, or Walloon system. It's quite complicated, and it means that pretty much every election between 1980 and 2010 is technically unconstitutional.
Well, it got better. It used to be that the Equal sharing policy was a firm government policy. Actually known as the Waffle-Iron system, which said that funds for Public Works would be divided 50-50.
Meaning that for example, when the port of Brugges was expanded, the Walloon region got (entirely useless) world tallest boat lift system.
Link. Another example was that when the Coastal streetcar system was provided with additional, Chaleroi received 50 streetcars as well, where it needed only 15. Worked in reverse as well, when Mons got a University, Limburg got one as well.
There's lot of crazy stuff in the past. The Catholics and the socialists had a bit of quibble about School systems in 1960, which now results in the fact that my hometown has 6 different schools.
Still, the fact that you can't do recounts means that I'm pretty sure, it can't be deployed in some countries. And the system might be as secure as you want, people's computers aren't.
You can do a recount right away, it just takes minutes as the votes are stored on servers.
Also Ukrainian Ranger, the influencing of voters by non-ethical reasons is something that traditional voting is also very weak against. Who says that everybody in a certain voting station wasn't paid off or otherwise influenced by somebody to cast a certain vote?
Pretty sure digital votes don't count. After you can't validate that those votes are the originals, without also ensuring that they can be traced back to the original voters.
Just arguing from a bureaucratic perspective here.