Dual CDMA sims?

I was curious if anyone had tried dual CDMA carriers on their dual sim G4s. My understanding is that for 3G cdma voice the device itself is registered as opposed to a 3G GSM which registers the sim, so only one CDMA service could be active at a time. Changing to another CDMA carrier would mean going through Verizon's or Sprints's activation process each time you wanted to change to a different sim (this was my experience with a 3 sim adapter). I'd love to hear someone more knowledgeable chime in on this subject and provide some feedback on whether or not this is how it would work with a dual sim moto G4.

I'd love to have dual CDMA sims because I have free service with ringplus (Sprint MVNO) but it's spotty in rural areas, whereas Verizon has the most solid signal in the remotest regions.....however I think it's a pipedream. I am aware that you can do a CDMA LTE sim switch and get data without a problem (I'v done this with a triple sim adapter), it's voice and text that I'm interested in being able to switch to, without having to go through the activation process. And because I need this voice and data in remote areas without LTE, VOLTE isn't an option.

I hope that isn't too convoluted or arcane a question, I realize it's not a common scenario. But with the Moto 4G being carrier friendly to all the north american providers (GSM and CDMA) and having a dual sim slot, it's the first plausible solution to what I'd like to achieve.