Please explain to me, what is the difference between a Guitar and a Bass "one octave higher than an EADG-Bass"? There are only 2 strings missing. You should consider ADGC, "A" the same as on a normal Bass on the 5th fret on E string.
A short scale Bass (30") has the 5th fret approximately on 22.5"
Look on my avatar pic, this is a 30", I have my left hand on the 5th fret, a very comfortable playing position.
The same difference as a guitar and an extended range bass played in the upper end of its range. Even though extended range basses upper registers stray into the same octave covered by a guitar, they sound, feel, and play nothing like a guitar. An ordinary four string bass can play notes in the same register typically played by a guitar. Still, sounds nothing like a guitar.
Take a look at some of the you tube videos of people playing a Marleaux Consat Sopran. It's within a half inch in scale length to my build and it is tuned EADG. It also sounds nothing like a guitar.
A lot of it has to do with string gauge. A typical guitar will have a set of 9's or 10's (I use 10's). The low E on a set of guitar 10's is .056. The E on the Marleaux is .080.
It also has to do with the feel of the instrument being totally different. Doesn't feel like a guitar at all, and doesn't lend itself to being played like a guitar. When you pick it up, you don't think "guitar with missing strings", you think "odd little bass."
I don't want to change the tuning for two reasons. I don't want to change the position a note is typically played, and I intend to use an octave pedal sometimes to put it in the register of an actual bass.
You may be overthinking this, I'm building it as a novelty and a personal toy. Maybe something my toddler son might like to play when he gets a little bigger (he already plucks the strings on my guitars with a wide-eyed expression - I'm hoping he will take an interest). I like building weird stuff, it doesn't have to be practical.