If a Marvel Spidey movie is made, I don't expect any cameos from any major MCU characters...at least not during the movie. Instead, my suggestion has always been to bring back minor MCU characters. My ideas were to include Peter working at the Daily Bugle and one of his co-workers is Christine Everhart and Peter watching on TV a news report of President Matthew Ellis (from Iron Man 3) attending a meeting at the United Nations. No need to force Tony Stark (although you could directly mention him and/or his company) or any of the major players there. Or Peter could even be at the University library and one of the books he passes by is "The Adventures of the Howling Commandoes" and this picture is on the cover:
Or course, since you don't like anything in the MCU outside of Guardians of the Galaxy, you would probably be enraged if these minor MCU characters showed up anyways.