Then you have no problems............
In the old IL2 original netcode the missions were not encrypted so you could go the the cache and retrieve the mission you just flew and rehost it or modify it.
The missions became encrypted (possibly due to 3rd party addons licenses being sold) so the missions become a string of -13687570393487152 instead of the actual mission name.
This means no matter what the mission is it or how you altered it will be re-downloaded into the cache and the edits the host has made transferred to the clients cache so you both fly the same mission
edited by the host, so no conflict in the missions being edited by the client, as he's not hosting it.
X:\IL2 1946 v4.11m\Missions\Net\cache