The way we've found works well for managing being in on both accounts is to have them open in different browsers-one in Firefox and one in Chrome, for example. Either way, it's important that contributions are attributed to the members making them, so the only things that the PA should be doing, really, is accepting trusted list requests or merge requests that no one else can. For most projects, a Leader can adopt a profile to make those happen, though, if the profile is 200+ years old, so only newer profiles, like those in Notables, would even need the PA to complete those actions. I know it takes longer if you're using just one browser, but it's important that actual "people" are seen making changes and contributions. The profiles are intended more as a way to gather and watch profiles.
The bulletin board comment is my bad-it should say public comments and I am off to fix that right now.