Re: 'M-o' ('facemap-keymap') has now been removed until March 10th 2021

[Paul W. Rankin]

> - with a prefix argument, toggle font-lock-mode "correctly" (i.e. making sure 
> that the buffer is unfontified when disabling)

This part is what shouldn't be in there. Calling `font-lock-unfontify-region' 
is the nuclear option to remove all text properties, including those that font 
lock doesn't "own", so to speak. As I mentioned before, I think you're getting 
confused about how font-lock and text properties work, and so what you're 
saying is "correct" is not so. Deactivating font-lock-mode does not and should 
not remove all text properties -- only those with the `(fontified . t)' 
property.