I remember reading reviews of the triple-action handles that said the added weight clamped to the back of the needle would flex the needle, causing the tip to go significantly off-center in the nozzle. Dunno if that's been fixed since. Seems like it would be an easy fix- just lengthen the part of the nut that's inside the handle sleeve so it never fully separates when pulled back, that way the handle sleeve would always be supporting the weight of the nut. Looks like the DCA handle as pictured in Dave's post may have that in hand (the nut looks like it might be fully supported for the length of travel).
Personally though, I'm with Dave: I cut the plastic bulbs off my Badger needles, not just because of the impact risk to the nozzle, but also because if I have to remove the needle for maintenance/cleaning, I prefer to remove it through the front rather than the back to avoid pulling any paint residue through the back of the brush. So having something clamped to the back of the needle would not only add risk, but extra faff to maintenance as well.
If I wanted to operate in "single action mode", a conventional needle stop IMO works better. Yeah, its still two motions instead of one, but it has the simplicity & consistency that's the point of single action, and without the needle/nozzle constantly open, there's much less clog and tip build up risk.