Good news. I just received this email from Kevin at Emporia. Apparently the flex sensors do come apart for easy install. I may not have to bug my neighbor the electrician after all.
Kevin (Emporia Energy)
Jul 20, 2021, 10:30 MDT
No need to remove the breaker, the Flexible Sensors will “snap” apart (at the base of the ring) so you can attach them similarly as the other sensors (clamping them around the wire).