Using this nifty tool called FretFind2D, I outlined a version of your proposed Sensi guitar according to my own multiscale design language of sorts. Check it out here.
Since the reach of the guitar is a 7/6 higher than normal, and most available strings don't take too kindly to being tuned up, an expedient solution would be to keep the top note around a 12edo/A440 "E" and go down from there, making the bottom string a kinda sharp C#/Db. The extended 27" scale on the low end would help keep such a note singing nice and clear, while the shorter 25" scale would keep the higher strings warm sounding and easy to handle.
Looking at the fretboard, it would be really nice to connect the "breaks" in the fret positions with curved frets that hit both distances, similar to True Temperament frets, so that you can bend to your heart's content.