I actually achieved this using the Turboslide to be able to switch on the fly from normal Richter to Paddy Richter. I raised 3 Blow up a tone so the harp's default is Paddy Richter, and I changed the distance of the magnet for 3 Blow to drop the reed back to its original tuning. It works. I pulled out all the other magnets and I have a harp that can switch from Paddy to normal richter just by holding the slide in.
However it has some issues: it currently can only affect the blow reeds, and for the smaller reeds if you try to adjust the magnet to get lower than a semitone it gets very unstable. Experimenting with dropping 7 or 8 blow by more than a semitone caused a very unstable note. its odd: the note slowly rises the more you hold it.
You can use the turboslide to create a sort of 2nd position minor harp as well as you can get the flat 6 out of 2 and 5 blow with it. Here we hit another drawback of the turboslide: it only works on blow notes.
To switch on the fly between a standard and minor tuned harp I'd need the ability to drop the draw reeds as well.
Another super fun tuning I've grown to love is "Easy Third". Easy Third drops 2 draw and 3 draw each a full tone so that holes 1 2 and 3 match the note layout of holes 4 5 and 6.
It would be great to have some harps that could switch on the fly between related tunings, that are the same size of normal diatonics.
My current harp case has 12 diatonics, 6 "minor tuned" harps, and I'm starting to build up a small collection of "Easy Third" harps for keys where the octave range makes more sense to play them in 3rd position instead of 2nd ("I'm looking at you Am")
So Turboslide is out unless you happen to switch a lot between Paddy Richter and standard Richter.
I'm looking for other ideas.
I know something like this could be achieved on a chromatic platform, and chroms are now more inexpensive than ever, but even these 10 hole chomatics are just.. too bulky. I'd still want something I can drop in a pocket, and I don't want to carry a case of 12 chromatic sized harmonicas (maybe I could settle for two dimi tuned chromatics)
A diatonic sized harmonica that could switch on the fly between default tuning and "easy third" would be so much fun. Just saying

Why Easy Third instead of Paddy for playing in 3rd in the lower octave? One answer: Because the 5th is a bendable draw in Easy Third.