I had asked Earl about getting these as an option and was told not an option, no further details provided.
When we were at the FMCA rally in Gillette there was a vendor table fro the See Level sensors. I asked about installing them on tanks that are wrapped with the aluminum covered insulation. They believed that the insulation should not be over the sensors, rather suggested the sensor area be left clear.
(There is an installation spec that the sensors need to be several inches away from metal)
In general, I would be cautious about using these unless you plan to remove the factory insulation from the black and grey tanks.