When you use the Custom Names feature of Plus!, you can set a custom name for them, which will show up in your contact list (and conversation window, if you want).
Go to Plus! > Preferences > Contact List > Custom Names and change it. You can use tags as (!N) for your contact's display name, and (!M) for their email addresses.
A limitation of this feature is that emoticons will not show up in your contact's display names in a conversation window anymore. A way to avoid this is to use custom names without emoticons, and using them in conversation windows too. It's either that, or not using custom names, or dealing with it
changing names
. I'm sure I once found a way to enter their real names in messenger+, but I can't for the life of me find it anymore!
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