I read that officers aboard NPR ships that have been captured will sometimes divulge information on their race's ship classes or a tech. If NPRs assign officers to commercial ships, wouldn't it be possible to raid said ships with FAC-delivered Marines to gain intelligence? Pretty much it would go like this:
1. Sneak a stealthy (e. g. low signature) assault ship holding Marine companies and a rapid shuttle into a developed enemy system.
2. Use very large passive sensors on the assault ship to detect enemy shipping.
3. After observing which planets ships seem to go between, set up on one of these shipping lanes and wait for a freighter to approach.
4. Once a freighter has approached, use the drop-ship to initiate a boarding attempts at high speeds.
5. Once the Marines have (hopefully) captured the ship from the civilian crew, you should get intelligence (if the dice rolls well, of course).
6. Transfer Marines back to assault ship, do whatever with the freighter (destroy it, stash it away, etc. )
7. Run away fairly fast as the enemy race probably would have realized you are there by this time.
8. Wait an appropriate amount of time and return.
Of course, speed would be extremely important or you would probably be blown out of the sky. I haven't tested this myself but I may be in a position where this would be highly effective. Can you see any glaring mistakes?