This is a very old suggestion and was even made as soon as the lock feature was introduced in Messenger Plus!.
eg: "
CookieRevised's reply to Boss Protection requiring password to reopen"
And with it there could be more features like "
CookieRevised's reply to Suggestion: Boss Protection"
Dunno why these
two extremely similar features where never merged into one though, as that would solve many things (not to mention make more room in the preferences for new features as it currently is full)...
Anyways, there is a plugin made which integrates, kind-of, both features and make it possible to do both. That is, locking messenger and hiding the icon:
http://360software.dakotabcn.net/umlock/index.html
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