Fear not, Roger has really got the shielding think figured out. He's been known for it since the 70's.
I received my first Sadowsky with singles a couple of years back and I thought the same thing. I was amazed at how little hum was present when I panned, and I live in the worlds noisiest house; short of strapping a beer sign around my neck.
I'm a true believer in the single, go for it!
Not to be deceived: Roger's basses are quiet, but they DO hum when the single coils are not at equal volume. Now, I get ZERO RF hum from my Sads, but single coils gonna hum.....