Let me repeat the option of buying a $289 Hagerman Piccolo2 as a "stopgap" for use with the Luxman MM stage - it will properly load the SoundSmith, and it will allow OP to discern if he likes the cartridge enough (I mean REALLY likes it) to keep pursuing its options. It can be sold to recoup funds at the end of experiment. Or it might sound good enough to keep in place for a while.
I used one on my Benz LPS and it handily beat SUTs which couldn’t optimally load that cartridge into my VAC Renaissance SE phono stage. No, on even ground its circuitry isn't gonna match the refinement of OP's Luxman or my VAC, but it will beat the crap out of any loading mismatch!
Mine arrived in a week from Hawaii. Like British Mullard tubes, it might not be what you settle on, but it’s a handy addition to your audiophile toolkit.