Hi chris
I had the same problem that I didn't got an inductive sensor reliable working with an an aluminum heatbed and a pertinax on top of it.
Tried also an simple optical sensor, the same issue. Some times it worked, sometimes it crashed the nozzle into the bed.
The BLTouch is working reliable and this is what I am using today.
I want to move over to Piezo Disk. There is a longer thread
here.
They are installed, but I still need a nozzle whipper/brush. Obviously when you measure with the nozzle you need a clean one.
The BLTouch has a big offset (17mm to the left and 40 mm to the front). What the piezo I can measure with the nozzle with no offset.
Not sure whether it makes a difference, but I will give it a try
Peter