Lots of added comments here:
As mentioned, installing more than one wire under a breaker terminal is generally not allowed. I have seen maybe only one manufacturer of breaker that allows more than one wire under a terminal. For those though I suspect you have to have the same size wire under both terminals (or with one gauge perhaps). While the Sense wire carries a trivial amount of current, the other wire that might be connected to that breaker may carry a considerable amount of current. I would not make the assumption that if there was a poor quality connection that the heat would cause the breaker to trip. That is likely, but nothing you should ever depend on.
I believe the only code compliant way to install a Sense today is by building your own pigtail and just wire nutting a the Sense wire to a properly sized wire to go into the breaker. While yes, if you land the Sense on a breaker directly which is not rated for that small size wire it is unlikely to ever be an issue (and this is how I have installed mine), but when it comes to inspections and NEC, the code is the code and what the breakers are UL rated for is what they are rated for. It is pretty cut and dry.
Note that the “ask” for solid core wire vs. stranded is not a big deal. I get how that might be hard with the molex connector. The actual critical “ask” is around wire gauge and electrical code.
FWIW, there is no way I would install the Sense wire and a much larger gauge wire under a breaker terminal that was not rated for two wires. That is asking for issues. You are either going to be crushing (and damaging) the Sense wire or you are not going to put enough clamping force on the larger wire to flow enough current across it (or both).
I figured the Molex connector probably had a wire size limitation. I am not sure how to deal with that other than having Sense build a wire with a butt splice in it from the factory, or select a connector that can accommodate a larger gauge wire.
This is obviously not a showstopper for most folks as clearly people are installing Sense units, but it might stop getting a UL listing or something (is Sense UL listed btw? - I did not look)