When I bought my first Integral there were no instructions. My opinion there is not to follow them to the letter.
When I checked the clearance of the control surfaces. All of mine needed some sanding.
You will find over time you will probably need to sand them again. So, check them often for a while. I know my first Integral I had to sand after a few flights and then once more. I check the clearances every time I put the plane together and get ready to fly. I don't think that is a QC problem, they may have had clearance when it left the factory. I think the material is thin enough it will deform to a certain extent for a short time and then stablize. Temperature can cause the composite material to move and cause a bind.

I may have mentioned this in one of my build posts, but I am not sure.

Carl