Payload, ultimatelly, should be the choice from who made the mission.
I would really leave it as FC/DCS is by default, maybe just enforcing an integrity check serverside. If we allowe free choice this could be a mess, everybody demanding payloads, dozens of different lua files, etc. In DCS:Ka-50 it is not a problem because with 4 pylons you don't have many combinations, but in FC you could really have lots of them, but I think ED default ones are more than enough for specific roles/task. If one wants to be multirole/multitask for an specific mission, perhaps we're doing something wrong.