I don’t know why the high line cars in AUS were so expensive back in the day but they were.
As to mass loading, I found that better than just beneath the table as a plinth, the mass loading worked well on the table on which the turntable sat - a heavy antique mahogany prayer table.
I eventually went to a big Minus K.
One thing I did do more as a precaution than anything, is clean the rail on which the air bearing travels- I use a non-shedding individual isopropyl lab wipe to do that before each play. Franc K thought it was unnecessary, but I don’t want the arm to hang up and torque the cantilever of my cartridges.
Just my observations- I’ll be interested in your take once you get the unit set up.
Dialing these in is far different than a pivoted arm. I don’t know what Holbo recommends, but the Kuzma likes to see a very tiny uptilt in the front right corner- beyond any measurement by "level"-- it is based on how the arm behaves at different intervals along the disc surface. There are not "null" points as such- I assume the mfr supplies a template and you can adjust the feet or plinth to get it to travel properly without worrying about "anti-skate" as such. It’s such a small adjustment, a slight turn of wrench is all it takes. I can adjust the stand, the Minus K and even the HRS platform to a degree. Get it right and it sings!

