Sentinels working together

Hi, sorry to ask this question if it has already been asked… I’m new to geomining, I should be getting my kit soon, and I’ve looked at previous posts and didn’t see this asked.

When I get my sentinels, if I give one to my wife for her keyring and I have one on my keyring will they just do a handshake once and mark GPS location at the first location they come close together? Or, if we’re driving around together, will they mark GPS location multiple times?

I’m just wondering how they will work. Will it be better to keep one off and just turn it back on at random locations to mark those locations? Or leave them both on and hope their handshake keeps happening over the various locations?

Thanks.