I held my DMM probes across Isense and power ground terminal points on the fussy pump for 10 long minutes and no chirp. Everytime the pump turned on, for a split second I usually got 0.02-0.03V, a few time as high as 0.12V before jumping to 0.28V. I did not check the other pumps as long, but the initial V was mostly 0.02-0.03V.
The alarm system becomes less and less sensitive to an unplugged pump as the wave pulse in shortened. The fussy pump is the most sensitive, but even it does not trip the alarm when the pumps are cycled at about 1 second. The tank's empty right now so I can't say for sure, but it looks to me like I'll be using the wave at a shorter pulse length than the alarm can pick up.