true type fonts don't work that way. Thickness, which is only assigned to the screen, is based on "curves" and TT fonts don't have those. Same as width (aspect ratio)... TT fonts have this built into their definition so it cannot do that either.
What PTC really needs to do is gray out those cells when a TT font is specified to there would be no question rather than have one assume these values are set.
Let's see what the new Creo 3.0 overhaul of annotation has to offer.