I encourage at least two tonearms, one with a removable headshell.
And then a SUT with at least two selectable inputs, PASS for MM, and optional settings for MC cartridges, thus only 1 phono input needed for any tonearm.
Best Stereo on main arm, Mono ready to go on second arm. Second arm removable headshell for quick change to other cartridges, yours or a friends.
Second arm, easy height adjustment for VTA, and if cartridges of various heights are involved.
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I've seen some two arm tables all; assembled, I'll post some later when I have more time if you are interested in the idea.
I personally helped a friend mount two Micro-Seiki Arms on this wonderful Luxman PD444
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We know what we have best. Me, personally, I couldn't be happier with mine. Importantly, I have the skills and tools to modify, mount tonearms which makes a big difference is a solution like mine.
I put my vintage TT together with help here. Bit by Bit, Plinth and Spinner phase 1. 3 tonearms selected separately, also with advice here.
All in, except cartridges, $5,000.
I started with two arms, and later squeezed a compact 3rd arm on, so I have Long Arm with MC, any other, and Mono.
Mine is Vintage JVC Victor TT81 DD Quartz Lock Spinner in a JVC Victor Two Armboard Plinth CL-P2, seen here
https://www.audiogon.com/systems/9511?_gl=1*bdv68k*_ga*NjQzNzE3MDA1LjE2NjQyODIxNDk.*_ga_SR0PMVVEN1*MTY3MTg5MDUwNi4yMDAuMS4xNjcxODkwODkwLjYwLjAuMA..