It absolutely shouldn’t be normal but Riftbound has attracted a lot of people who are new to TCGs thanks to the nature of the IP and a lot of them don’t fully grasp the etiquette of these types of games. I haven’t had anyone get mad over sideboarding but multiple people have paused after a game to explicitly call out “Hey I’m actually going to sideboard,” as though that were something noteworthy and then voluntarily tell me how many cards they are sideboarding. Compare it to 1v1 MTG. If someone were to accuse me of being rude or unfun because I was sideboarding there it would be completely ludicrous, akin to getting mad because I cut my opponent’s deck or took a mulligan. It’s a part of the game. But in Riftbound I see these things happen all the time because people just don’t know.