How do you accomplish this in-game?

quit and reenter as another civ

Ok, I was under the impression it was possible to do this during the game.

I have the same question....

What does it mean to "quit and re-enter"?

How, in other words, can you switch the country you are playing as, in the middle of the game?

You quit to the main menu (or disconnect otherwise) and reconnect to the - running - game. Then you get to choose your civ.

Ok, I was under the impression it was possible to do this during the game.

Python popups cause issues, so all of them were disabled.

You quit to the main menu (or disconnect otherwise) and reconnect to the - running - game. Then you get to choose your civ.
how do you do that while in hotseat?

you can't do it in hot seat, and you can't choose a later civ. It's technically not supported by RFC MP.

you can't do it in hot seat, and you can't choose a later civ. It's technically not supported by RFC MP.
well, actually I found a roundabout way

could be nice to share it then :D

While in staging room set civs you want to switch to later as "Human", start the game, play until that civ respawn. After that you retire from civs you don't need. I didn't try, but maybe you can even do that from the very beginning and turns will be skipped until needed civs.

Good idea, I want to try this with RAND and see if there will be less OOS than in regular TCP/IP connection.

Good idea, I want to try this with RAND and see if there will be less OOS than in regular TCP/IP connection.
Would be interesting to know results of your test =)