Fitting Kitchen worktop in U shape kitchen

Hi, I've been fitting my own kitchen and about to proceed to worktop next week. All base units are levelled front and top. I’ve made a cardboard template for the longest run (piece (A) in photo) which has 6 corners and some of them aren't 90 degree. The walls has slight bows and bumps in couple of places but are generally parallel to the fronts of base units. I will have tiled splashback afterwards.

Here's the plan (not in scale).
View attachment 56209

Before I dive into the actual...

Fitting Kitchen worktop in U shape kitchen