Only older versions of FontCreator prior to Version 7.0.1 (released 21st June 2013) used TTF as its native format. Since version 7.0, FontCreator has had its own native font project format *.fcp.
Anyone who already has a license for FontCreator would find a font project file more useful than an OTF or TTF as it includes details like guidelines, notes, and export settings.
The latest version of FontCreator can export TTF, OTF, CFF Outlines, WOFF 1.0, or WOFF 2.0 from the same project file, so the OP could then make minor modifications, and re-export with or without hinting, etc., as required.
Comments
You need to be sure the license if the font you are modifying permits you to do that. What font is it?
Anyone who already has a license for FontCreator would find a font project file more useful than an OTF or TTF as it includes details like guidelines, notes, and export settings.
The latest version of FontCreator can export TTF, OTF, CFF Outlines, WOFF 1.0, or WOFF 2.0 from the same project file, so the OP could then make minor modifications, and re-export with or without hinting, etc., as required.