Custom Grail, frame/fork advice

I’m getting a custom ti frame that I want to match the Canyon Grail (size XS) as closely as possible. However, since Canyon doesn’t publish its fork specs, I’ve had a lot of problems with the design. The builder’s (Waltly) expectation has been that I would present them with fork specs so they could build the bike, and my expectation was that they would present me with the fork specs so I could buy the fork. It has been quite a learning experience for me.

 

Finally they reverse-engineered the fork specs and came up with a 385mm fork with a 45 degree rake as what I would need to match the Grail’s numbers. The frame spec comparison is below, and attached is the frame drawing. I’d like to get some comments on this frame and particularly the fork and fork trail that seems a little long (6.74 cm, calculated to get close to the Grail’s short wheelbase). I’m pretty sure I can find a 385/45 fork, but it will take a bit of time and may not be from a reliable manufacturer. I currently ride a Carbonda 505; their fork is 385mm with a 51 degree rake, so that’s what I’m leaning toward. I just don’t quite understand how that will affect things, so I've been reluctant to move forward with the design (Waltly has been amazingly patient!). Any comments will be greatly appreciated.

reach 373 / 372.8

fork length ? / 385

fork rake ? / 45

fork trail ? / 67.4