Hi Tom,
when measured cold, a serious diagnosis is not possible. Engine at operating temperature after 20 km of hard driving is really warmed up.
I also use my powerful charger in parallel, since the gradual drop down of the turning speed has a negative effect on the compression pressure.
An even distribution is important, more than 15% is bad.
You are familiar with the test with oil injections, I think?
My revised engine (head planed 1 mm) shows 5.4/5.2/5.4/5.2 AtÜ.