As a general rule, any person who can really play, but is excited about playing a locking string guitar, has never played such a guitar. Don't let tham mess with it. They don't know what they are doing. Anyone who can really play, and who has experience with such guitars, will be reluctant to play it. They will ask if you have another guitar they can play.
Perfect tuning is impossible because of the physical layout of the guitar. It doesn't matter whether you have it tuned for 5ths between the nut and second fret, octaves at the 5th fret or using harmonics, whatever. It is always a compromise. If you know the different tuning methods, then you will retune your guitar for different songs. Ones that use a lot of open chords sound awful if you tune for octaves at the 5th fret or use harmonics. Use 5ths at the second fret instead. But switch back for playing lead up the neck.