What you said was:

To avoid the huge numbers, they were replaced with "n"

as though this were somehow an indictment of the argument.

Dragging in Omega to represent the huge quantities for the human seems to have been a desperate move.

Anyway, the important thing is: several people have already explained how a finite system can express an unbounded utility function without having to explicitly express numbers of unbounded size.

Well, that's OK - but the issue is what shape the human utility function is. You can't just extrapolate out to infinity from a small number of samples near to the origin!

I think there are limits to human happiness and pain - and whatever else you care to invoke as part of the human utility function - so there's actually a finite representation with bounded utility - and I think that it is the best approximation to what the brain is actually doing.