Where is this information from? I thought overseas maintenance costs just meant high distance costs made by the ocean between. Will overseas cities still have normal distance costs in addition to overseas maintenance? Wouldn't reduced overseas maintenance be bigger boost to Imperialistic, because it can't be reduced any other way except Ikhanda/Courthouse, if they work for overseas maintenance too. Does this mean that FP and Versailles don't give any help with Colonies?
Info from the Info Center thread on colonies
Overseas Cities will cost Overseas maintenance, as long as you own them, FP+Verssailles won't help
By giving your overseas cities to your Vassal (ie Colony) you don't have to pay ANY maintenance on them anymore (although they increase the # cities Maintenance in your cities)
The idea is that
Distance Maintenance has all type of solutions (FP, Versailles, State Property)
Overseas Maintenance was put in so there would be a reason to use Colonies (the only solution)
Number cities maintenance is almost Impossible to "solve". because even your Vassal (including Colony, Capitulated, and Voluntary Vassals) cities add in to what it costs in your cities.
So Imperialistic would be ideal for reducing that, because it helps you maintain a large empire of yourself OR Vassals.
Jails+ Custom Houses would be good, to represent 'Meddling in others affairs' through espionage+trade
Besides those two though, I'd just stick with Fixing the previous bonuses.
Food+Hammer Bonuses for the Settler are absolutely necessary (because It basically is a bug like early versions of overflow were a bug)
Improving the use of GG would also be good (partially as an overall game fix)