I don't know the answers to these but i offer a couple of comments.
Some theories claim BM was a digital mastermind who could disable his Truck telematics, spoof SMs phone messages etc etc. I dispute that as he actually gave away lots of digital evidence which implicated him. His mistakes are actually the ones you see in multiple cases - where being aware that he can be tracked by his phone, he simply puts it in airplane mode. But forgetting that location data is passive and also that the 'black spots' reveal when he is up to no good. He then goes to all the dump sites revealed by his telematics. This isn't the action of someone who is good at covering his digital tracks, but rather someone who had relaxed, and then made the mistake we see in lots of cases revealing incriminating actions before/after the fact.
So I don't think there was a complex scheme with his truck. We see it active in the evening, and we see it active in the 3am hour - but in between there is a digital blackout, because he doesn't have either with him IMO. He knew he had telematics. So IMO he simply took a vehicle without it. That is much easier than jiggering your truck. Rather, he believed the truck and phone would provide his alibi by showing up at home.
For the same reason, I doubt there is an accomplice, and I doubt he took someone else's vehicle. I think he just took the older RR.