" I really love with highish end used/open box parts bought because my tastes are Waygu, while my budget is nice brisket."
Great analogy.
""What would you recommend over the Parasound JC3+?"
Definitely a nice SS unit. A tube phonostage will give another perspective. To my ears, just as your tube pre does, it delivers a more "organic" convincing presentation. Since you're open to used- Manley Chinook or Herron.
If you do get the "new" itch, the new Prima Luna all tube phonostage looks inviting. I say that not having heard it, but owning PL gear for many years, likely it follows the PL lineage of value,performance and price. I'll demo one when I get a chance.
Primaluna EVO 100 Tube Phonostage — PrimaLuna USA (primaluna-usa.com)
If my current tube phono doesn't make it thru a visit to the shop, it will be on my hit list.
You have a setup that does at least 90% of what uber setups do. The room setup, as you likely know, will make or break a system.
"After a bit, I’ll probably add another time arm and go for something risky."
I'd also look into Sota/Phoenix RoadRunner tach/speed regulation.
Eclipse Roadrunner – Sota Turntables