As i fell i still didn't write enough, few more words.

I'm sceptical about this:

First, if your idea cannot be implemented using the mod framework, then it's OK to submit to it UserVoice. You can either word it as a normal feature, or word it as an idea to expand the mod framework to support it.

If your idea can be implemented using the mod framework, next determine if a mod already exists to accomplish it. If a mod already exists, then it's OK to submit it to UserVoice as an idea to convert a mod into a built-in feature. Note that these type of ideas will only be considered if the mod is already pretty popular.

I've seen in uservoice ideas completed/declined because they are avaiable through mods. But the more important thing is if they can be done well. So examples:
- limited deployment - it's fine idea. But playing with mod can be quite annoying. There is no way mod will tell you that you are deploying too many. If you do so troops will appear somewhere else or nowhere. That's not good experience.
- one way connections - to be honest, i didn't even try this mod, even if i like the idea itself. As far as i know capabilities of current mod engine, it can just remove orders to move from A to B(where defined). So you need, to check forbidden connections in the mod settings, memorize names (you can't click on it to check where it is) and find where it is. It might work if there are only few such connections on well-know map or very small map, but it sill be incovinient. On the other side - proper GUI(like arrows on borders between territories to show you can go only one way and unability to issue such order) could make it popular feature.

So, you are telling that if mod will be pretty popular the idea can be built in, but it will be hard for mods to get popularity because of different shortcomings of (current) mod engine. I don't know what's are further plans for mod engine, maybe it can be done better later. But at this point judging idea's popularity simply basing on mod's popularity is just not valid. At least in some cases (as ofc. there are mods that can work pretty well - name Nuke Card for example)