do we really need any more 10mm options
You're correct that, for a cartridge only 1 in 10 shooters has ever heard of, it's a great selection. But still my response is yes, we need at least one more option.
One of the nice aspects of 10mm is that it's reasonably powerful and at the same time, reasonably compact. It's ready made for double stack capacity and that's been accomplished in an all-steel pistol that has virtually the same grip size as a standard 1911 (i.e., the Witness Hunter).
The option 'needed' is an all-steel double-stack single action in 4" to 6" configurations for under $1,500 or so. Custom 1911s costing more than my monthly mortgage payment are, for me, just plain silly, and I don't need no fancy guns, I just needs the ones that shoot.
I measured my Witness Hunter grip and I believe it is less than 1/8" thicker than a 1911 and for my medium-sized hands and stubby fat fingers, it's actually more comfortable
than a 1911. Understanding that I think the 1911 may be among the most comfy handguns ever built, that's saying quite a bit. My Big Point being that fine-looking, excellent-handling and nasty-accurate double-stack steel guns in 10mm are a 'natural', I think shooters need a few options.
If the OP's question was "what single 10mm firearm would be your No 1 choice if it were made", then my answer would be something like the equivalent of the M&P 45 Compact, but in steel. If Smith did an M&P 10mm Compact just like the 45, I'd buy one tomorrow, quite literally. But steel would be preferred for a little extra heft.