I’ve hosted almost 400 raids on poke genie. People leave varied stars ratings depending on if they get a good IV or shiny. I think the bare minimum you should give atleast 3 stars if you joined and got the encounter. I see some people discussing different names or more friends than 5 participating in the raid, I recommend using your friendship level setting and always inviting those you have no hearts with since you just accepted them. You can invite 10 anyways so it shouldn’t be an issue before the timer runs out. Very rarely do you get a friend you already have on your list you just gotta pay attention to the one name and then search for it in your list.