[chillingeffect]

Keep sight of your goalposts.

This isn't a discussion about whether a source encourages its use or not. It's about whether it's a typo or a correct spelling.

Your quote above, in which 'gage' is implicitly referred to as a spelling further supports that it's not a misspelling.

I don't know how to state this in a more friendly way. These are merely facts documented here for verification purposes. If anyone's immediate reaction to verifiable facts in the face of an imposter spreading misinformation differs from gratitude, I would fear for their ability to take in other easily verifiable facts.