I think at this point if a case isn't Whitestone friendly it's probably not a brand worth buying. Screen protector friendly cases have been all the rage since Samsung decided to curve their screens.
My guess is the the Whitestone is a little bigger than the Samsung film. My neo hybrid doesn't come close to the factory screen protector. Maybe Spigen designed the case based on the Samsung protector. I do like the extra protection on the sides of the phone.My wife and I both have Spigen Ultra cases, and both have pushed up on the Whitestone dome on the s20. Mine may be user error since I can visibly see my screen protector is slightly off center. But my wife's is aligned correctly and it still has lifting due to case.
Just throwing this out there for Google to index, in case someone is looking for some verification.
I mounted the Whitestone Dome Glass screen protector on to my Galaxy S20+ and it fits fine with the Spigen Neo Hybrid case without interference.
I have the S20 Ultra and the Spigen Ultra Hybrid. No issues. It's close but still has a little gap between the edges. I also got the Spigen Rugged Armor but haven't opened the box yet.
If wasn't for the install holder and I'd have to do it myself I'm sure I would of screwed it up.