I don't use one on my Ptrans but I've noticed the power drain on it is practically non existent (unless you use all cerbs i guess), so even with a BS scanner, I'm betting you can still bust some hulls with that set up.
In the end, if you are concerned with running into caps, take a bomber and/or gunboat escort. At the very least, a scout can make the difference on whether you even have to cross paths with that capital ship or not, regardless of what it is. And any GB/Transport could use a BS scanner with minimal nerf and probably see that cap ship waiting down the lane or down near the next jump gate.
@ Kosa:
I agree that the fighters now are pretty much useless to pirate in unless you're in a group of 2 or more, and that still depends on the ship being pirated (other fighters and freighters being about all that is left, and don't let that freighter get to cruise speed!)