Just to verify when using a collector limpet you need to drop into the zone. Look on the left panel and select anything you don't want to collect then fire the limpet? Can all that be done before the pirates spawn or are we talking during the attack?
There's two ways to scoop.
- launch a limpet without targeting anything. It will slowly[1] collect anything that isn't on your ignore list in range
- target a container and fire, which will quickly[1] pick up the targeted cargo only
In other words, you can slowly pick up everything with a limpet, or quickly pick up a single thing with one limpet.
Class 1 collector = 1 active limpet
Class 3 = 2 active limpets
Class 5 = 4 active limpets.
Class 3 is more than enough to scoop everything before bads show up, if it's not a threat 0 site, using either method (as long as everything else is on ignore)