ProMods

I was surfing on the Internet and I found that Promods is compatible with some maps. And then I thought: how big can the map be with other maps combined? If anyone knows the best combination of mods that are compatible with Promods to make a huge map please post here. Thanks.

Take a look here to see what's compatible: viewtopic.php?f=42&t=14523
The most "stable" solution is ProMods + RusMap. You might want to add Southern Region Map to it, for slightly more hardcore experience in its most southern part.

I agree with Vøytek. You can add other maps also, but it can be a pain to make them all work and most are not realistically placed on the map or are of poor quality/out of scale compared to scs/promods/rusmap. I have added southern region map and enjoy it, but will probably drop it when I update to 1.27 as it is out of scale and will eventually interfere with promods.

I deleted SRM after switching to 1.27 because I already explored the most interesting part of it (yes, yes, I'm already playing on 1.27 for testing purposes after building new PM, CAP and TCP myself, from our source files)
As said above - other maps might be worth a try but I didn't enjoy them. Project Balkans is a small map that will be overwritten soon, when ProMods covers the same area. Egypt is interesting but it's not as good as I'd like it to be
I was also using EAA like a 2 years ago but it wasn't really good - copy-pasted cities, a lot of bad looking forests. Maybe now it's better but it has compatibility issues.

(building new PM, CAP and TCP myself, from our source files)

That's cheating !!

I can delete them and then you'll get a version that won't be tested and probably won't be working properly. It's a necessary cheating

Better having him cheating on testing it out in 1.27 than having too wait even longer for a working version for 1.27 :p

That is one cheat code that I would love to have