Control: reopen -1 No, the TTF file is not the preferred form for modification in this case. This is demonstrated by upstream publishing vfb files.
It is furthermore the case because the font contains Visual True Type hinting information, which is sourceful in vfb but is compiled to bytecode in the TTF. So I am reopening this bug. Please do not just close bugs that you have not handled. I volunteer to make the change but I expect that you would revert the change (as you are about to do for other fonts). So I want to be sure that I am not wasting my time.
