Thank you so much

You can, but it would not be a good idea nor would necessarily work. The mod adds a new unit (the ITA agent), and any new unit added after game start can cause save game corruption (all unit types are given a number, adding a new unit can cause the numbers to change, which can change large swathes of the map. Usually it only happens to modded units, but I once turned all spearmen into crossbowmen in one of my saves). Furthermore, the game has a very weird way of loading events from new mods (sometimes they work, sometimes they don't) which means the ITA agent might not spawn at all sadly.

TL;DR : I really, really don't recommend it. A new save would be preferable.

One question ¿could I activate the in the middle of a game?

Great work

Alright, with this update every plane should be available and navigable. I ended up implementing you suggestion @fabian with the shovel and the gem of flying, because otherwise some of the planes were just royal pains to move around in.

That'd be too powerful, given the general utility of these items for everywhere else. Furthermore I'm almost certain both are always accessible from Elysium, though difficult to navigate. Plus the objects of flying would only cover the commander. I'll probably do a plane teleport ritual, maybe with some scrying (or just a blind suicide hop like the scrolls).

Idea for Sky and Agartha, perhaps the agent also sells the shovel item and one of the objects that allow to float/ to fly???

Good to hear ! I tested it on my end but there's always times where something doesn't work for other players. Well, enjoy !

Works like a charm, test with a vanillla and a mod faction