I've been making progress for the alternative pulser, here on github, based on MD1213 and TC6320.

It does look nice, with jumpers to select voltage levels, as well as easier connectors:

It seems the first pulses are up to the task: 25, 50, and 75V have different echoes strengths!

Soon to be on Tindie for the first batch - twice the HV possibilities, same price as the first module!