I have the same tool and charger and only noticed the out-of-spec voltage after trying to charge the tool with a regular USB-C cable and charger. It's really disappointing someone thought this is a good design.

Newer revisions of the tool don't seem to have this flaw though. They only come with a USB-C cable and no charger in the box.

Also thanks for reminding me to put a big sticker on the charger with a warning!