I lived in nullsec looooooooooooooooooooooong ago but i seem to remember something about you building up the rats that were in the belts.

Example, if there was a good spawn with some high end BSs, youd leave alive a frigate and the same group would respawn a bit later, something like that. If it was a shitty spawn youd kill them all to get a fresh one. Not sure if thats still how it works.

That said just make sure you're being careful with that much firepower.