This is an interesting idea.
I've thought about a similar mode changing slide myself, but not in the context of modal Richter tunings:
viewtopic.php?f=9&t=275#p1707
In the language of your post, instead of switching between major and minor in the same key the first tuning in the post switches between D Aeolian and D Lydian. The way I think of it though, is that it switches between D Aeolian and A Ionian (natural Dm and A major). I don't know about the traditions you play, but it's not uncommon in some Scandinavian tunes to switch tonality to the major dominant for some parts of tunes that are otherwise played in minor.
On paper, my setup has one more accidental but less chords for the minor modes. In the key of D mine has both a major and a minor tonic chord(D + Dm), both a major and a minor dominant chord(A + Am) and the subdominant major parallel (C). If the modes would continue in a spiral, it would have a minor subdominant as well. With your choice of modes, Aeolian and Ionian, you would have all these, plus the choice of a and minor subdominant as well. This would be useful in many modes.
I often miss the sharp fourth in tunings where it's absent, at least when playing melodies, as it's the leading note in the major dominant scale.
Summing up, I think I'd prefer my modes to play Scandinavian tunes with focus on the melody, while yours probably work better to play chords in most kinds of minor music and better to play melodies that don't have the quirk of the sharp fourth. Some of the lack of chords in mine could be made up for with arpeggios using the slide.
I never got around to realise any of these tunings though, so I can't say how they comparing terms of playability.
As you seem to be much better than me at realising tunings I look forward to hearing the idea at work
