I never read much of the code, I guess it shouldn't be that difficult.
I'm going to guess it would be fairly difficult. From what I remember, tapatalk was using a complete copy of one or two of the Source files. Just my $.02.
According to the repository, it just requires (huge) changes to them, or have I missed something?
Well, in their mod they have a quite big replicate of the "Sources" directory at:
https://github.com/tapatalk/tapatalk-smf2/tree/master/mobiquo/include
Honestly I'm not sure why they include them, it should be investigated.
Maybe someone should ask the SMF guy.