Use Unity EFB Toolkit to develop EFs in C language
Yes Unity provides a SDK-C companion software called EFB toolkit. You'll be able to create some EFs and then enrich the existing libraries of Unity. Of course you can do the same with internal DFB but there is two advantages with developping in C. First, EFs runs faster than DFB so ou reduce scantime. Second, it's of course completely protecting your know-how. Once the EF is created, nobody can open and read what is inside. Main drawback, it's not possible to modify the inputs/outputs and inside program of an EF while used as an instance, whether it's still possible with a DFB.
Hope that helps.