Consider making core between L6 and L7 thicker
Currently it is just 0.1mm, being the thinnest dielectric in the PCB, and it's between signal layers with lots of traces running in parallel which would increase crosstalk (the two layers are closer together than they are to their reference layers). A simple fix that shouldn't have any consequence would be to use 0.125mm for L2-L3 and L10-L11 (improvement, increases inter-plane capacitance) and make L5-L6 0.15mm.