Can't comment tech details of specific mods ATM, but, to my knowledge, *we never ever targeted any user mods*.
In the carrier crew mod case, most probably it was broken by the change, required to implement SC the way it is. Frankly speaking, I never knew there was a user mod like this at all. We can't keep track of everything users create.
Yes, there's lack of documentation, not enough communication, .. many issues, really.
DCS is an extremely complex piece of software and you will be surprised how small the core DCS team is.
Other sims may have better docs, better support for usermods, but they allow much less. These are related matters - the narrower your APIs are, the easier it is to document and support them, but the lesser (is it English language still?) they allow to implement. One will never be able to implement warfare in MSFS or XPlane.