You have to take care that you fold that into a BEGIN block, because use is evaluated at compile time.

If you have a script like this:

# modify @INC
use Some::Module;
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the use is evaluated before the # modify @ING line.

You see, it's not as easy at it looks, which is why use lib $path; is recommended. (It checks for duplicate entries in @INC as well, which is another advantage).