In my mind it seems that if you have low cylinder pressure than air is leaking past the piston rings and it wouldn't be making it into the exhaust manifold/turbo to spin the exhaust turbine wheel, so the question is can excessive blow by caused by low cylinder pressure or leaky rings affect peak boost? I say yes but its all ways better to get other opinions.
Also do you think this type of blow by could cause enough air bubbles in the oil(pan) to affect oil pressure?