I just checked these out as a possible travel guitar for my "
trip". They do have chromatic models (4-string and long-scale 3-string) and "long-scale" (I have no idea how long) 3-string models.
I'd be tempted to tune the 3-string in either (you guessed it) Major 3rds (good right-hand finger picking work-out), or a root-third-fifth set-up. The four string is really begging to be tuned in either all fifths, or a fifth-fifth-Minor 3rd (mini-NST) fashion. String gauge & tension might need a re-think, because they actually use banjo strings.
Ray