There is a trick to that my friend. I use to be the same way. Low level limpets last up to 3 minutes upon deployment. As long as you dont give a target to a limpet, it will run to the time period picking everything up that isnt on you ignore list. Just im a cheap loser. This is what i run. I deploy one limpet AFTER i hit my charges. And it picks up all the fragments with plenty of time to spare.
You will find yourself jettisoning them. So dont over do it. Fill cargo to 30% and you will be laughing.