Hello Bart,
I hope you have more success than I did.
I built a first JSN-SR04T sonar probe for a well with a pump where clear water arrives, this one also has 2 crossed support bars for solidification.
The probe worked perfectly out of the well, but as soon as I put it in, the numbers were off.
Then, I tried the experiment with a VL53L0X laser probe, same punishment, it worked perfectly outside the well and inside I obtained aberrant values. Is it due to the clear water, the reflections ? I don't know.
Finally I built a mechanical tool that works. It's less sexy, but it works finally.
Tasmota manages switches.
In any case, congratulations for your work and your sharing. 
the probe that works:
