I would like an answer to this too. In my mission, there are a couple of units who execute an .sqs file in their init lines, the .sqs files change the loadout of the units. This works fine but when I add a briefing to the mission, the units start with default weapons.
I have no idea wether the .sqs files are not executed at all or if they are overridden by briefing defaults.
Thanks in advance,
Nicolai