Personally, having gen 2s and other cars with coated steel ropes on my route. The idea of applying anything to the belts is borderline scary. I would only even apply that Otis belt conditioner after seeing full documentation and getting it directly from Otis. I wouldn't dream of concocting up my own stuff to put on there. Can get people killed.
As far as noise, I've got a bunch of gen 2s and they're the same way. As far as I'm concerned the customer is getting what they paid for. There's nothing wrong and nothing to fix or address. It's simply a caveat of the design of that equipment. Even ecospaces don't do that. Because they use real ropes.
If the customers not happy, you could always point them in the direction of your sales folks for new elevators.
