Motostoke would be a great traveling stage.
Wyndon Stadium would feature Pokemon battles in the background. Attacks from Gigantamax Pokemon can sometimes reach the fighters and cause different effects on the stage.
Rose Tower would constantly move up and down, occasionally stopping so a Pokemon can hop on the elevator and cause a ruckus.
Slumbering Weald would be like Spear Pillar and Unova League where the boxart Legendaries interfere with the battle (assuming they aren't one of the fighters on the stage at that time). Layout is mostly the same but made larger to give fighters more space.
Energy Plant follows the same concept as Slumbering Weald, only the focus is on Eternatus and its battle with the Legendaries.