What about using something like:

https://www.amazon.com/DROK-80-300V-Voltmeter-Multimeter-Transformer/dp/B01MRZAFAF/

Put them anywhere you want.  At the breaker box or at an outlet.  Even make an adapter to be portable.  It's kinda future proof.  Lots of different brands and price ranges.

some even have the split transformer:

https://www.amazon.com/Current-Amperage-Voltmeter-Multimeter-Transformer/dp/B07JB9B2QL/

Prices are all over the place but can usually find one of the brands in the $10-$15 range.