You know what I think would definitely work? Injecting the plant with flavenoids (for example blueberry, lemon, cherry, vanilla) to enhance taste after harvest. Roots do a pretty good job of filtering things like that out, so it's difficult to enhance flavor via the root system. However, I've read of people chopping plants just above the medium, then placing the stem in flavored water for a week or so (think x-mas tree). In one example, they used vanilla, and the buds not only tasted vanilla-like, they even were tinted a light brown (think carnations). What made this possible, was bypassing the roots - something your injections do also.
I'm not sure I see the practical value of shooting up your plant to feed it (perhaps I'm overlooking something)... However, I'd be very interested in seeing somebody enhance bud-flavor or color subtly using a similar method.
Though most good cannabis tastes about perfect to me just the way it is!
No matter what, I can't help but give kudos for trying something different and outside the box.