Presence is interesting because it is an instantaneous spell to cast but with a duration of concentration. My old interpretation seems compatible with the new RMU description.
I've always treated the instantaneous casting as letting the caster know how many minds are nearby and very roughly where they are (all ahead, mostly ahead, mostly behind, all around, all around but with a bigger cluster to the right, etc).
Then further concentration, possibly over many rounds, allows gathering more details. Family members, close friends, and long-time travelling companions, etc. can be identified with absolutely minimal activity, but determining if others have been encountered before would take concentration (and memory just like recognizing faces). Each round of concentration could identify one mind and determine the distance and direction to within a foot or so. After the mind is located it can be targeted with spells like Feel (and if in sight can also be identified more precisely for physical attacks or other interactions). Each round the caster can choose to focus on any one identified mind or the next closest unknown mind, either overall (in any direction) or within some arc. (i.e. Just how close is that presence behind me and has it been moving toward me?)
Even though it's an instantaneous spell for casting purposes, using this in a crowd is going to require a significant amount of time to get anything useful out of it.