My plugin uses both IPs.
If they differ, it makes you two studies and not just one.
The study includes both have been used to connect or register.
In the list of results there are buttons to eliminate a friendship (or pending request), block / unblock, access to the profile, list of conversations you have had with it and many more things.
The admin can also see and delete private messages with a single click, log in as that member, edit their profile, suspend it and many other things with a single click. It is based on the information of many plugins if they are installed, and if they are not, then the information that they would get from them is simply not shown.
The admin sees everything, of course, and each thing can hide the others forever, establish if it shows according to user roles or let the user decide adding it to the privacy settings.
In this case, if a member chooses not to allow himself to see who has blocked him and whom he has blocked, he will not be able to see the blockages of the others either.
Some images ... But they are provisional, first I write the code and then I fix the data presentation. It is an evolution of my "userInfo" plugin ... but much improved.