Simultaneous tunings?

I am sure I'm not the only person who thought of playing in two tunings at the same time with one synthesizer so I'm wondering if anyone found any interesting combination.

As an example of what I am talking about...

Take my hexaphonic guitar to midi converter - it may be advantageous to have strings 1 through 4 in 18 ET but strings 5 and 6 in 9 ET - that is my thought.

And on an aside

Anyone interested in my guitar to midi converter may be interested in this thought - by running a synthesizer on each string via the hexaphonic pick up top midi conversion I should be able to effectively shift fret positions by applying a transposition on my input to the synth.

For instance - in 19 ET a major triad on the bottom 3 strings has this pattern:

E string 3 rd fret
A string 4 th fret
D string 4 th fret

By applying a transposition of +1 I should be able to make the triad a simple bar across the lower 3 strings in 19 et.

Chris