Steve at VAS has a BIG VPI setup, with a uni-pivot arm base, with a nearby shelf, with a collection of uni-pivot arm wands with various cartridges. He tests, and demonstrates cartridges he builds/re-builds there.
It sounds terrific!
The base has VTA on the fly, ... and each arm wand has a mini din connector to a nearby din/rca junction box. pull the din connector out, lift the arm wand off, set it down, place the other arm wand on, connect it’s mini-din to the junction box, ready to play! Single arm base is one set of cables to phono stage which is adjustable/pass for MM.
Steve’s setup takes more area, there is no dust cover, thus not for me. My 3 tonearm setup is 3 gimbal arms, less area, removable dust cover. Mine is 3 sets of arm cables to a SUT, front selector for which arm, then select loading or Pass, then off to MM input.
More than 3 cartridges, a friend’s cartridge, it’s gotta be mounted in it’s own headshell for the Acos Lustre Arm with VTA on the fly.
Switch headshells: if cartridge body is a different height, adjust VTA (easy), then: azimuth has to be carefully confirmed/adjusted, both tracking force and anti-skate adjusted. And, when I go back to my cartridge/headshell: reset VTA, azimuth, tracking, and anti-skate.
I’m very quick, been doing it for many years, and got the hand coordination of the Acos-Lustre arm down, tools at hand, but it ain't instant.
I did not see Steve reset tracking or anti-skate when switching arm wands/cartridges, I need to ask him about that.
I gotta say, 3 cartridges he built (2 for me, 1 for a friend) sounded terrific on his uni-pivot arm wands.