You’re over-thinking this. The alert could have been for temperature, not voltage. All you need is a long AquaBus cable, a PM2 module, and a temp probe. Probably costs less than most of your frags.
Although I do have a small powerhead in my sump to disperse 2-part that occasionally seizes up, so I monitor the watts and get alerted if it goes above 5w. Normal operation is about 3w:
If Output EB_7_SMP_FLO Watts > 5 Then ON