Actually, we don't even need a plugin to do this, it's already an option in the Plus! Registry Entry.
quote:
HKCU\Software\Patchou\MsgPlus2\your@email.com\Preferences
NameOnSignin
If not empty, Messenger Plus! will use this value to change your name to a default one every time you sign-in on a specific computer.
The best, and safest way to change this would be to download
Plus! Tweak
Run the exe, select your email, and scroll down on the left side to "NameOnSignin" Here, you can select what name you would wish to have on signin
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