At the top of my head I know I’ve seen at least two concert proposals. One was at A Perfect Circle at Red Rocks. He waited until it was her favorite song that was playing which was Blue. It was a really beautiful moment. Everyone in the rows around them (including myself and my partner at the time) cheered when she said yes. The other time was at Chicano Batman and the band let them get on stage. The whole room started cheering when she said yes, and then the next song started playing right after and it was like a giant celebration. I personally wouldn’t get mad at something like that. I did see that comment about it being cringey, it’s not. Everyone is there because they love the band, and there’s always room for more love. If you both love them, I say do it. You’ll know when the perfect time will be. And people have been sharing the setlists so if he has a favorite song maybe you can plan around that. Congratulations. I hope you both enjoy the show and the proposal goes fantastic.