A few have started recently like Rex and Ajoesmith, but I have not used them for that so I cannot recommend.
Maybe in another year there will be plently of good options, but right now Chief has the market mostly to himself.
He announced a new run for July with signups starting as soon as in a few days or in another week or two.
There is no magic way to "get on the list" ; you just have to watch for a new post from him announcing it and sign up.
He will not sign you up otherwise, there is too great a demand and that wouldn't be fair so it is first come / first serve on the signup sheet.
His sheet is usually on multiple forums at once so just becuase you are first on 1 forum does not mean you are secure.
Sometimes repeat customers may get a little bump too, but hard to blame him for that.
If you want a shortcut, send Vac your watch for some other mod, as Vac and Ziggy I believe have blanket approval to be on chief's list/run each time he does them. He charges a fair fee to removve and reinstall the crystal if you are having him lume or service the watch at the same time.
I have one with Vac right now, so I went the shortcut route this time!