SUT With a Manley Steelhead RC?

I own a Manley Steelhead RC and am using as my main cartridge a My Sonic Lab Signature Platinum.  MSL makes their own SUT that I have been thinking about purchasing, but I'm wondering if it's necessary with the Manley.  I find the Steelhead to be the best sounding phono preamp I've ever owned, but I'm always wondering about ways to make it even better.

I sent a message to Bob at Bob's Devices, but his reply to me was ambiguous.  He made it sound at first as if there would be little sonic benefit, and also seemed to say that his SUT would be superior to the one inside the Steelhead.  I tried to ask more questions but he went radio silent after that, and if I try to call their phone number I can't seem to talk to anyone.  This is not a complaint about their company, BTW.  I've heard nothing but good things about his products.

Any useful advice is appreciated!