That would be better, but ultimately, you can do a decent vibrato without the lip sensor, so a simple software option would be fine. Turning the vibrato, which is robotically constant speed and depth, would sound almost as bad. What they need to do is add a switch in the app, possibly for each custom sound. Honestly, if there was any way to reach them, I'd have several suggestions. The musical commubnity is unanimous about the vibrato.
As for sounds, it's true, with some effect manipulation, it's passable, for a minute. Even the very best sounds of the YDS are only tolerable for a short time. The very best, if you can get really good at a few things, is the harmonica with distortion and echo/reverb adn some shaping. Some of the things I refer to are the analog bend controller and certain typical arpeggios and licks.