If someone had a purely resistive load they might be able to empirically test the charger output voltage change based on probe temp. But from what I read, it’s pretty small change( -5 mV/*C ).
But, what’s being considered is using the probe input to turn off the charger and that is sounding quite plausible. There maybe a side effect of a warning buzzer though.
Exactly. Someone needs only short the sensor or break the connection to see if it stops.
I have a Zivan here for testing, but not a lot of interest. 
I’m charging now and will pull the LED/sensor plug and see what happens. pulling the plug(LED and sensor) results in up/down continuous beeping from the Zivan. Put the plug back and it still continues beeping until I cycle AC power.
But I charged without the sensor until the LM335 chips arrived and what I did was cut off the sensor end. I think my capacitor on the little PCB had shorted and that’s why my sensor went bad. The DIN has 3 wires for the LED(1/2/3) and 2 wires( 4/5 ) for the sensor.
The side effect of the beeping is going to be a PIA unless you really want to be told when the charging has stopped.