Ideally I would want to play a standard concurrent-turns multiplayer game with friends, then save the file and strip out a scenario map once it's sufficient advanced that I can plug and play in GMR. Unfortunately that isn't possible because stripping a map out of save is not a feature that was ever written for Civ V (it was last available in vanilla Civ IV). What a boon it would be if such a thing were possible. Alas.

I have just started using it, but you could always set the starting era to industrial or something.

yes you can do that - I actually enjoy the early game and if you use the GMR Client it is not that much overhead , as if you manually download and upload the saves.

It also depends how many people are playing. I generally play 1 on 1, and if we are both online for a few hours we can get through quite a few turns.
I also play against my wife, and sometimes we will just play hotseat on my PC, and when we are done for the night, upload the save as usual.

Yes, it can seem tedious, but what is the (actually possible) alternative?

Two follow-up questions:

First, so with eight or twelve players, all on at once, it's not that bad?

Second, are there any scenarios you would suggest for later starts that give you more to do at the beginning of the game?

6 or more players is pretty hard to handle to get them on at once. My suggestion is to make the turntimer not at 3 days :) . My experience in the beginning was that I lost Half of my 12 players after the first turn was done 3 weeks later .

Generally look for people who are play active - the amount of points they have is no guarantee for activity but its an indication.

Regarding later starts I barely use it because I like the early game. What I did was taht I spent the money for more gameslots - but don't overdo it. With 30 something games you have enough turns to do, but its easy to loose the overview whats going on in a game.

I'm organizing one game right now, setting it up so that all of the players are online at once once a week. People dropping shouldn't be an issue, but if tedium might be.

It really is a shame that they don't have a way to toggle between standard mode and hot seat mode. Standard would be so much better for early game, with hot seat being good to keep the game going between times when you could get everyone together.

That's a problem for Firaxis though.

I doubt it's a very difficult thing to write, code-wise. I mean, you could even do it yourself, if they'd written the utility for converting a game save to a map save that they had in vanilla Civ IV. And it would have a such an awesomely positive impact on the game's multiplayer...it's a real shame.