I would also like a modding section.
So far I've only tweaked things in .csv files, like unit speed, hp, obvious stuff. Increasing unit speed seems to negatively impact pathing, so I'm not sure how far that can be safely pushed. But I've stumbled into some other interesting things, like tweaking how units organize themselves in battle groups (formations) and battlegroup templates used by the AI.
I tried creating a map so I could create a MapScript in order to set up mock battles to see how various combinations of units fare against others. Making a sandbox, so to speak. I can't even get the simplest of maps with 2 seeds to work. When I select the new map in the game setup screen it seems there are zero player slots, so I'm curious if others have had luck there. Even if I could get it to work, I'm not sure how to run the script. Maybe there is a hidden console with the necessary commands.
I tried an interesting test changing the number of units to spawn per batch of T1 units. I set it to 30 (from 3) and the game crashed as the first batch completed
I set it to 10 and 6 came out. Setting it to 1 seemed okay, but who knows what is actually going on inside.