I'm using the "Invite checked subscribers..." option to invite existing subscribers to my current mailing list to subscribe to a new mailing list. I find that the profile field values in the new subscription overwrite the existing profile field values, regardless of whether the "Preserve any current Subscriber Profile Fields information" option is checked or not. So if the new fields are blank, all the profile information is lost.
The documentation for this feature seems a little confusing - it says "If you'd rather have the information you've just submitted to replace the old information, check this option." which is the opposite of what I would expect, for an option with the label "Preserve any current Subscriber Profile Fields information".
But, as I say, checking it or unchecking it doesn't seem to make any difference. I'd really prefer any existing information to be preserved by default, and only overwritten by the new information if explicitly requested. And ideally, a non-ROOT administrator shouldn't be able to overwrite existing information at all.
PS. This is on 4.1.0, I've also tested on 4.2.0 beta 2 with the same result.
PPS. The problem only shows up with "Invite checked subscribers", when using the "Subscribe checked subscribers" the profile information IS preserved if that option is checked.