Opinions from other repair techs re: replacing rubber roof?

I see it like this
1. tell the customer he can pay to replace the luan (insurance won't cover it)
- or -
2. he can take the RV to a different shop (you won't do it the other way).

Considering the time involved to prep the surface vs. a remove and replace the difference in cost can't be more then a couple of hundred $'s. If I was the customer, I'd raise hell with the insurance company but pay the couple hundred if I had to. Either way your problem is solved.