I made a very minor edit to an OpenType font: I added a new Stylistic Set. And Exported the font back to an .OTF file.
However it’s rendering significantly differently, and not as well. Left is original, right is after edit in FontCreator Pro 9.0 (Build 1916)
Is there some setting I can do to leave the font in tact with just the new stylistic set added?
On the export I did leave hinting set to Keep Original. The new font file is 94k. The original was 62k.
The original font contains CFF (Postscript) based outlines, which are converted to TrueType based outlines on opening with FontCreator. Then on export they are converted back into CFF but have lost the original hinting.
You could try to see if exporting as TrueType works, with Auto Hinting, but it will never be 10% equal to the original due to differences in hinting and conversion (rounding).