Alas, I’ll have to learn to indicate the right level of cynicism more explicitly on here.
As cynical but slightly more in earnest: if voting rights were only given to those who can prove basic reasoning abilities, it might actually make a difference. Since there is no reliable way to prevent authorities from abusing such a criterium, I see no other option than to have no restrictions on any generic criterium. Perhapa a voting obligation would be more effective.
To summarise: use a terminal server system if you can, using a desktop for the end user that can be made to behave like windows (or another concept that works for your demography), and have the whole setup in a NixOS configuration that you manage in git.
I see that https://github.com/ltsp/ltsp is still going strong.