I'm sorry to exhume this topic but I'd be glad to get the source code as well especially since I develop on exotic host hardware (OpenBSD, Alpine Linux, macOS) and requiring a Windows VM to run a command line utility to convert a font sounds a bit tedious. What are the reasons besides the need to kept the fnt_cvt.exe file proprietary? I mean, are there such secret in the custom data font file format?

You'll help lot of people by releasing those utilities.