A good tip for when you post a public comment on a profile, Paul, is to check the activity of the profile manager, if the profile has one.
I looked at your contributions log and checked for your 4 most recent public comments; one profile was orphaned, while the other 3 had managers who haven't been active this year.
Even if the profile is orphaned or has an inactive manager, go ahead and post useful comments, as one or more of your fellow WikiTreers may be following the profile or related profiles. Just understand that you may not receive any response to your comments.