I think, if I were in your shoes, I'd be trying to control bubble formation. To do that, I'd be interested in reducing nitrogen absorption at depth, where it occurs fairly quickly in the blood. You're already doing that by committing to using the highest percentage Nitrox mix that is safe at a given depth, and diving it as though it were air. I'd also spend some significant scrutiny on my ascent procedures -- ascending rapidly in the deepest portion of the dive, and slowing the ascent through graduated stops in the shallow portion. Ambient pressure is one of the powerful forces limiting bubble formation, so keeping the ambient pressure high once you have passed the offgassing limit will be very useful.
On dives with a very shallow maximum depth, it's dubious whether the use of a high O2 mix will really make a difference. Nitrogen absorption is so small at those depths -- there IS no NDL for a 6 m dive, to all practical purposes.
If you're talking about doing a gas switch to maximize offgassing in-water on a moderate dive (<30m), you most likely won't be affecting bubble formation much, because it will already have occurred before you reach your gas switch depth.
I know I'm not answering your question as to how you can get certified to use hot mixes without doing deep dives, but your question intrigued me from a medical and decompression standpoint, so I spent some time thinking about it, and that's what I came up with. Nitrox for bottom mix and careful ascents should really maximize your safety, without doing gas switches. And it's much more fun to dive without those pesky extra bottles . . .
