if you sign it or not you still have the liability. You assume that someone is not smart enough to track it back to you if it is not signed.
I am a bee keeper. I used to sell my honey at the local tree hugger store. Then I got a little worried. If you give honey to an infant, it can kill them. It was not worth the price of insurance to be covered, so I quit selling it to them. My new customer used it in their wine. Now I only have 2 hives, and give it away if I have any.
It was not worth the risk of having my personal assets attacked, or the price of a lawyer to defend me. My personal liability umbrella will not cover me for business liability.
Like I tell my kids, "life is full of decisions, chose wisely"
Fleener