SUT - electrical theory and practical experience

Hi, I am looking for some real world advice. I recently purchased a new LOMC (Etsuro Urushi Cobalt Blue) that has an output of 0.25mv and 3 ohm internal impedance. I use an Allnic H-3000 phono preamp. An audio friend has the next step up (pun intended) of my cartridge with similar specs. Not sure what phono pre he uses. He swears by the SUT he’s using with it (Luna Cables Rouge):

My question is:

With the Allnic’s design, is it likely that I would achieve a significant improvement in sound quality if I were to add the right SUT (the Rouge may or may not be “right” for my cartridge specs)? I must say, the cartridge sounds great with the Allnic but only compared to the last cartridge I was using, a Kiseki Purple Heart, but maybe there’s a chance I’ve left something on the table?

Thanks Lew. Yes, there is a MM input. I wasn’t sure if the transformers in the Allnic were being used in the same role as a SUT plays. And yes, it is my understanding that Allnic hand builds the transformers and uses permalloy cores, which seem preferable to those with SUT experience/expertise.

I guess there is no harm in borrowing one to try but given that good SUTs are quite pricey (for a passive device), there would need to be a decent audible improvement for me to keep one in my system.

Thanks for the link and the commentary. I guess the first step is to borrow one that is ballpark the “right” one (I think windings ratio is the spec) and see if it wows me. I did try the Allnic SUT into an EAR 868pl MM input but was underwhelmed. But that was one cartridge ago. Maybe that would just replicate the sound of the H-3000 anyway.