What type of batteries?
The MultiPlus can act as a solar charge controller, do you need the extra MPPT devices for added capacity?
I’d leave the BMS until you get everything set up. To my knowledge, the only advantage of having the MultiPlus talk to the BMS is to get state-of-charge information, which you can also get from a shunt.
The Victron gear should just give the BMS’s all they can and let the BMS do the limiting once the batteries are full.
I don’t have any experience with JK BMS’s but they have RS485 so they should be able to talk to the MultiPlus. I’d wait for a better answer from someone more knowledgeable, or see if you can find the answer in the Victron manual. Maybe YouTube has some info. The OffGridGarage channel has a lot of Victron/JK content.
I doubt they’d mark non-dangerous, buried by the lowest bidder, no paperwork fiber cables. But you never know.