Multiplus-II randomly started overcharging my batteries last night causing it to repeatedly crash

Not sure what you mean, but before I was running the Multiplus in standard out-of-the-factory mode. I had no ESS assistant installed on it; I simply had it connected to the RaspberryPi GX with an MK3-USB cable.

Now I loaded the ESS Assistant onto the Multiplus and set the ESS Mode to “2” which, according to this documentation, should allow me to manage charging via Node-RED.

For the Low Battery warning I will need to check the battery configuration using the VEConfigure tool, I assume. I probably set the low battery limit too high. As it is now, it is giving a Low Battery warning while the batteries are still reporting 49% capacity.

Edit: I just realized that 2 of my threads are crossing each other. The ESS Mode 2 is another issue I am having discussed in this thread.