Here is my newly completed build!

Matt black aero gravel frame in size XS with integrated cockpit and Campy Shamal wheels with 50c Victoria T50 tires.

Shimano GRX 827  1 x bike groupset
Sunshine 11-46 cassette
Pass Quest 48t Aero chainring (no spacer add on and no issue for chainstay between chairing with 48T )
No brand saddle
Shimano XT chain
Shimano 105 Road pedals

Shimano Dura Ace with 4iiii dual Power Meter 170mm crank arm

I didn't have any particular difficulties with the assembly, except for a Pass Quest Chairing blocking the 4iiii Power Meter. Just slight modifications to fit in the 4iiii battery cap.