Why can’t they use a water based poly? It won’t yellow as much as oil based. I’ve never heard of bleaching the poly after application. Usually they bleach the wood first, but I wouldn’t bleach white oak.

https://www.familyhandyman.com/article/water-based-vs-oil-based-polyurethane-floor-finish/

I think I just misread your text. Sounds like they are bleaching the wood. Again, I wouldn’t bleach white oak. It’s pretty neutral to begin with. I wouldn’t suggest a gray stain - finishes are warming up again and warm browns are in style. How do you feel about a natural look - no stain, just a water based topcoat?

The standard "Raw" looking whitish white oak is bleached, toned, and then protected with a water based top coating. If you want it to be the look of raw unfinished oak, it's not a single step process. It's a big big upcharge because of all of the steps. Wipe it with denatured alcohol to see what it would look like with a plain water based clear. If you are OK with that look, then tell them that a plain waterborne clear is fine.

I don't want the standard raw look though. I want to keep the warm tones, but bring out the darker tones just a little to give it depth. So you mean a plain waterborne for the sealer? thanks!

@Susie I don't know what they meant by bleaching. It's only a veneer, so you'd think they need to be careful with it. I agree that gray is going out. I like a bit of gray for the grain running through, but I wanted the base to be more neutral and white toned. Thanks!

Get some white oak pieces and have him make samples.

If you want white oak that looks like white oak, just clear coat it. If you want that manipulated popular finish, then you are going to have to bleach it pale first.