What I'm gonna do is get some sort waiver signed by the customer.
In there it will have that I've explained all the pitfalls and regardless of that the customer still insists to go ahead with the topping, and we will not be liable for it ... so, I can't get fined, prosecuted or claimed upon for insurance and will make more money doing what stubborn people want.
My website has pics and 3 pages on the subject, that'll be sufficient to clear up the issue, attach that to the waiver ... bingo!
Tomorrow I already have a quote for a "lopping", good place to start.