Insisting on an AO knife limits your choices significantly. AOs typically are found on cheaper knives where the spring action can hide poor tolerances. The exceptions would be Benchmade and domestic KAI offerings. Have you looked at the old Onion ZT's; 0303, 0350 or 0200?
I'm irritatedly-well-aware of that limitation, and that's precisely why I posted this! I was kinda hoping there were some other AO fans who were deeper into the Biz than my dumb self, and might spew forth their picks, wishes, off-the-radar choices and whatever else here!
Why do you need AO? If you could succinctly share that, we might be able to suggest manual knives with acceptable action.
Oh, I don't for any reason need it, I just really like it! I live close enough to the suburbs of Denver that my time is split between (newly, and ᴛʜᴀɴᴋs!) autos-OK and autos-banned jurisdictions, and while I freely admit I have no disability or other pressing need for a spring to replace a slightly-harder-flick, but lockup's always so positive and even if I (can) pinch exposed blade and ignition-start the process it's right there for me, and, well, stupid but it's so delightfully mechanical, if that makes any sense; an unseen, nearly uncredited assist that at the very least results in a reliable crispness, an irredoubtable soundness, and a satisfying sound, as well.