Yeah, it's clear to me, I think.
To give you an exampe, I had a char that became ruler in a Monarchy. He was elected Regent, but I could readily change my own title to Grand Duke, as well as all other council positions. Changing from 'elected' to appointment was also possible from day one, as well as changes from 'elect quarterly' to 'monthly' or 'once', and 'all vote', 'only Lords vote', 'Dukes vote' or 'Lords representative'.
In short: you can customize everything, as long as you stay within the same system of government