gftools-fix-unhinted no longer useful?

[simoncozens]

There's some chatter about the fact that the addition of a prep table via gftools-fix-unhinted is actually making the rendering worse on FreeType (because then FreeType's own autohinting is turned off). We should review this and consider dropping fix-unhinted.

[RosaWagner]

fix-nonhinting also set the gasp table to full blur for what I understood, and this is still needed for unhinted VF. So maybe just drop the prep table thing but not the gasp table thing. Or switch to dehinter tool directly.