Very slightly smaller than you specified (It's .08mm thick, you said .09 as your smallest) but I really have to recommend the Spyderco Chaparral. I first got the knife, used, opened it up and started to cut the envelope it came in. I thought it was sharp, because it was so thin. It was skipping off of my fingernail, though. Sharpened it, and wow, what a cool knife. Not too small, but feels small. It's weird. Fits in the fifth pocket well, but in actual use, feels more substantial, even though it still is very much a small knife.
On the other side of this, you have the Police 4 LW (K390 preferred) which is only 0.110, well within your range. It's a long, stout backlock, and people malign backlocks, but they're solid. I carry one of these every day, almost. It's a real pleasure to use. If you ever appreciated the Military, but found that the blade was too thick for you, you may like the Police 4. You want a special steel, so the Police 4 LW with K390, very cool stuff, is almost a hundred dollars cheaper than the Military with special steel (S110V). And I prefer the steel. Not talking bad about the Military, just talking good about the Police!
Aren't XHP and M390 pretty different steels? Do you just mean you want a quality steel?
Spyderco
Police 4 - 0.11, K390
Chaparral - 0.09, XHP
Dragonfly (wharncliffe) - 0.09, K390
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Those are my real recs based on what you said and what I think is best, from what I've actually used. Had some other things to consider though.
Somebody rec'd the special S30V or 20CV Seki Spyderco models like the Delica/Endela/Endura series, which is all well and good, especially if stainless is something you need, but if it isn't... that Dragonfly, my friend, in a wharncliffe, you will not regret it. K390 is wonderful.
They make a 20CV Yojimbo 2, and while the spine's thickness is greater than you desire at 0.16, the hollow grind is dramatic, and the blade is very slicy as a result... You can get it in regular S30V, but versions are made, from what I understand, in 20CV, S90V and M4, but it sounds like you at least somewhat value stainlessness as you are asking for pretty stainless steels. I love those Yo'2s...