I'll add my voice to the mix to help boost this conversation up in hopes of getting an answer as I too have need of this same service.
Unfortunately I can't recommend anyone yet in the limited searching I've done. All the ones I wanted to get ahold of are long gone and out of the game or just plain not offering the service any longer if they are around still :
Ban
(Ban Tang) is out
norcalblacktail
is out
AZTimT
is out
REK Knives
is out
I've reached out to other sharpeners both here and abroad who have showcased similar work and no luck there either. Still other sharpeners I've reached out to don't really offer the convex edge we're after.
I've started thinking about just buying the equipment to do it myself but it's not going to be cheap I imagine if one wants to scale this up and offer it as a service eventually.
My thoughts were to reach out to a few knife makers who do work I admire and look to have done similar type work and see if I can get any bites. This is my last ditch effort before I begin hunting down the equipment and form the necessary skills to do this myself. I'll report back with my findings. Probably have a dozen or so people to reach out to.
And because every thread is better with pics, here's some old ones I keep admiring of what we're after (this is from Norcalblacktail's old knife mods blog) :