Concerning your code: given that sub uncomment_one is never explicitly called in what you posted, you may have over-reached in your diligence to follow the guidance ( not exactly "rules ) of this forum.
I put that code in a sub on purpose. The performance impact is triggered by the mere presence of those variables in the code, not their actual use as part of the execution of the script. And so there is no need to imagine a situation where those variables would be actually needed, only one where you'd need to load a module that contains those variables in a sub your code doesn't actually call.

In reply to Re^4: Impact of special variables on regex match performance by roubi
in thread Impact of special variables on regex match performance by roubi

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