Can't say anything about the JBD, but my 200 amp JK-BMS is now 4 years old and has been flawless, except for one balance lead connector that failed and caused a shut down. Once I fixed that balance lead, I have not had any issues and it is keeping 360 amp hours of cells all balanced within 0.003 volts at all times.
My second battery bank is split into two 180 amp hour groups. Each group is using a much cheaper $60 Daly 100 amp BMS with just 0.060 amp passive balancing. These have also been working flawlessly. I have not had any issues at all. But I do wish I paid a little more and got the "smart version". It's a bit annoying to not be able to look in at the cell status. I have to use a meter and measure the cells by hand. That balancer only tries to do anything when the cells are more than 0.015 volts apart. And last time I measured, they were all within 0.010 volts. So with well matched cells, the small passive balancer is good enough.
Of course, my system is being very easy on these BMSs and cells. My peak current has only just hit 120 amps. That's just 60 amps on the 200 amp JK-BMS and 30 amps each on the two 100 amp Daly units.
I may change out the Daly units for "100 Balance" ones. It looks like they are plug compatible with Daly. They are made by the same parent company. They have an active balancer, but it does have some quirks. It does not start balancing until ALL of the cells are above the start threshold voltage. That should not be a problem for a well behaved pack, but an LFP pack with one runner could be an issue.
Another thought I had was to get a stand alone JK active balancer. Make up a cable and just plug it in to the balance lead off of the Daly and let it balance the cells any time I see them off a bit. Since the balancer has the bluetooth cell monitoring app, I can just plug it in once in a while to read the cell voltages. If they are off, leave it plugged in for a day. The only issue is when the balance lead is pulled from the Daly, it will take that string of cell offline.
