About to get hearing aids, have a couple questions about fitting/programming

I am about to select a pair of hearing aids for mild/moderate hearing loss. I have had a second hearing exam from an Audiologist and it basically mirrors the results from the first test done by an industrial hearing protection company.

The insurance will cover a “2nd best” level of aid, which I understand to mean the Phonak Sphere 70, Oticon Intent 2 or ReSound Vivia 7.

I have ruled out the Phonak since it lacks Auracast which I expect to use regularly. I would choose the Intent 2 unless I decide I prefer replaceable batteries, resulting on the ReSound Vivia 7-61.

I have the following questions…

I read the hearing aids may be “locked” by the provider, does this mean nobody else can program them with Genie?

How does one determine their device is locked, do you (or another provider) need to actually attempt to connect to the HA?

Would it be reasonable to have another provider quickly connect to the HA to verify access?

I don’t plan on reprogramming them, just want to ave a backup plan to change provider if needed or DIY.

Thanks for any replies.