Yes on the waiver if you can actually get it signed. A great number of builders see it as an excuse and not what it is.
What I’ve done to work around that is offer 2 prices. One with razors and the understanding that it may get scratched, and another estimate thats nearly double that price to keep the razors in the truck.
I’ve had a lot of success with that approach.
As far as a solution, you should consider buying some oil flow.
I used it with a white pad.
Stuff is great but the smell gets on your nerves after day 1.
It will also help to have a punch list for each unit that you create yourself.
I use 2 units per page.
It helps me when I bring a dry erase marker with me and after the glass is cleaned, I circle imperfections and scratch’s in the glass.
At the end of each day, when you do your walk with the foreman or your contact, they may not give a care about it, some do but its a very few of them, the main reason why I do it is kind of for my benefit. In their mind I’m showing them I care about the quality of my work and I didn’t just start yesterday.
This way, when another trade comes in a scratch’s your glass (like painters’ helpers who screw up and blast your window with paint and try to get it off later) or the welder who pits your glass, or the stucco guys who grind the window with lathe…they are probably going to believe it was someone else when you say so.
Just a little input for you that may or may not work for your outfit.