Well there is a sneaky way around this,if you don't mind losing political parties.
You change the name of the governments to reflect a 'higher level' of government
achieved.For example,everyone starts at level one government ,as a nation gets better at governing it self and acquires more skill it progresses to the next level.
The actual types of governments will take the place of the parties.
And since you can set these in DA the Drengins might be Communists,the Terrens,might be
a Democracy ,the Iconians Fundamentalists,and maybe the Arceans are Imperialists,
the Altarians ,a Constitutional Monarchy,and so on.
Then you would vote to change the government not the party,like what happend in the former Soviet Union.
Which would bring you to the last roadblock ,bonuses and penalties for adv govs,which are hardcoded.To me people gaining power to the point of social instability is reflective of human nature therefore no Government is immune.So for me accepting the increased necessity to keep people happy as you progress is natural.
It works for me until governments become moddable !