Some - but perhaps not the best.
Too right. The best tend to use the tools required to get the music they want to create. If that means using a capo or changing your tuning, so be it.
But then the classical world is fairly hidebound. Lurking on the MMIF where instrument builders go to chat, a few of the pro luthiers there have had classical guitarists find that their "unconventional" instrument designs sound better than the "regular" ones, but they still need a "regular" one for taking grades because they feel the examiner would mark them down otherwise. Bit of a sad state of affairs really.
Capo-wise, I do look down a bit on the partial capo, because I can't personally see an application for it. In particular, the claim that it lets you play DADGAD or other altered tunings without retuning or learning new fingerings is provably false. But other people here have found uses for it in providing drone strings specific to a tune/song, so if it fills a need then fine.
Some folks can be a bit toy-happy though. I once saw a guy called Amrit Sond and was very unimpressed - his entire set only consisted of demonstrations of "hey, if I use this gadget or this technique, it does this". There's a big difference between using a gadget or technique and actually making music with it.
I admit to being a total gear-freak myself. :-) I love my digital FX pedal, because it lets me dial in exactly the amp tone and FX I need for a song. Similarly, my newly-acquired Variax lets me pick just the right guitar sound for a song. But even though I theoretically could use, say, a banjo through fuzz distortion with auto-wah and ping-pong echo, I wouldn't because it wouldn't fit any song I could think of. And it's worth noting that the electric guitar fraternity rather look down on both of these as not being "proper" tools for the job. (No-one said that the classical crowd had a monopoly on hideboundness...)
I guess this means that for each gadget, you'd need to look at it to see whether there's any possible niche it could fill. Capos, there's a clear need for them. Partial capos, maybe a small niche, but it exists. But Bert's hypothetical auto-guitar, I can't actually see any way it could contribute to guitar-playing. Maybe someone else can suggest some way it could be useful, but I suspect it falls into the same category as the famed "Bumper-dumper" - a technically-possible curiosity, but not something that anyone would ever need.