No Mike you don't understand. Yes the 4000W gen only puts out 33A so the wiring is fine. The QD 8000 on the other hand has 66A on the neutral and a larger neutral wire is needed to the ATS and then on to the CB panel. BOTH of these wires will carry 66A at full gen output. And the ATS gen neutral and relays need to carry 66A. Hence the wiring to the CB and ATS is sized for the larger load which is 66A for the gen neutral.
You might be interested to know that even on my prior rig with a QD 7500 Monaco used a larger neutral from the gen to the CB panel.
And you are making way less of this than it needs to be.
I'm certainly fine if the OP wants to use the current wiring. But he can make an informed choice.
