I know we are talking homebuilts here, but aircraft certified under
Pt23, that have a heated pitot, must have an indication that it is off
or inoperative. (See Pt23.1326)

I remember years ago, we had to retrofit all our corporate aircraft
with pitot heat warning systems. There was an AD that required it
after a crash where the heat switch was left off. All of the systems
I'm aware of measure the current to the probe(s) and give a light or
ICAS message if the current is low. Some larger aircraft I'm familiar
with pass the power wire through a coil to measure the current, which
I'm sure is a bunch higher on a turbine aircraft. Maybe the same
concept would work at 7 amps.

I think if I was building an aircraft, I'd work towards certified
standards, so I personally think having a heated pitot and warning
system is a good idea.