If I leave before Jafs has completed picking up cargo, will he still get it all? Or will he somehow be reset such that no cargo was acquired. Thanks.

I just tested the following:

* Jafs turned all the floating cargo to light blue and started picking them up. Before he was finished I went back to the base and checked the inventory. There was lots of new cargo.

I have not tested:

* Instead of heading back to base, head toward a distress signal and try to capture more stuff while Jafs is loading at the first site. See if the same thing happens this time.

If you go through a jump point or back to your base, Jafs will miraculously transport all the loot back to base and be ready for more. It works the same if you fly far enough without jumping out. You can test if he's done by trying to summon him to the new location. If he nags about "Not being able to do six things at once" or the like, you aren't far enough yet.

This also works well if Marauders jump in and start shooting Jafs (they usually go for other targets, but it happened to me a few times that he dropped everything and ran away).

So if you don't feel like defending Jafs while waiting that he finishes loading, just jump through a jump point or LDS away a few thousand km and he'll get home safely with all the loot.