I understand the need to surface this feature but I’m reluctant to add it as a second primary button.
I like this idea quite a bit. A just-in-time “did you know about proofreading” message when someone is composing a post or reply (perhaps over a certain character length?) seems like a great way to educate members on this feature.
@chapoi sketched out this idea which I’m hoping she doesn’t mind me sharing 
