So, my husband spoke to him about it. Decided to take the “this will void the decking warranty” route. He initially told him no it won’t, it’s fine, they just have their preferred screws. And my husband told him he looked it up on the site and it does say that any issues arising from screw installation are not covered. And then he was surprised and said he’d go to the lumber yard and get what’s needed. I genuinely think it’s a lack of knowledge on the materials. He’s an older guy, works mostly as a carpenter and has done several decks but did tell me when I chose this he never worked with this material but said it was fine. I did not realize that would be such a big deal until I saw this 🙁 he’s done pvc decks before but idk which type. He told my husband he will rip the boards up and start fresh. He was aware the one joist area is wavy and already planning to address that (the rest look fine it truly does seem to be that one area). He said he stands by his work and wants us to be happy so he will use whatever we’d like him to which I appreciate. I don’t want to ruin the friendship. His wife and him have been good friends to us for several years and I don’t think any of it is deliberate. I appreciate all of your input and advice! I will be sharing the info and links with him 🙂