My MC pre eschews the use of circuit boards, has no wiring, every component is soldered to the other components in free space ( in a 3 dimensional array to minimise component interaction as is done in the Mares Connoisseur ).
For your next build you might want to look at eliminating the circuit boards, and eliminate the resonant and hystereses inducing metal chassis, and all switches in the signal path. If your circuit is as good as you claim, then eliminating the circuit boards, resonant chassis and switches should be an audible improvement of a significant margin.
The answer to your question is yes, the same Reto Andreoli that builds cartridges selling up to $50k and for which he has an 18 month waiting list. Personally I don't use his cartridge but he has some interesting ideas on cartridge tracking/cantilever/stylus profile and the issues of how to minimise distortion on playback. He is a fan of the cantileverless Ikeda MC that I use which is very close to emulating the cutter head action in playback resulting in very low mechanical distortion and phase anomalies on playback.