I've tested it and starting in Post-Imperial Age gives XP for your home cities. Deathmatch or Supremacy.
I got mine from 16 to 19 and from 19 to 22 for India.
I also got from 20 to 21 for French DM home city using Post-Imperial Age.
Note that custom maps still won't give XP.
Good Gaming!
[This message has been edited by murdilator (edited 06-03-2018 @ 02:30 AM).]