This is not the normal way to exit a sub. If you try to exit a sub via last, a similar warning would be produced:

Exiting subroutine via last at a.pl line nnnn
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It is not a good idea to suppress a valid warning. You are simply cheating on yourself.

The style you are getting into can easily introduce bugs. This is the same as using goto. You are altering execution path in a unstructured way.