The Booster Course Pass tracks are heavily ported from Mario Kart Tour (the mobile game). As a result, compared to the base Mario Kart 8 Deluxe tracks (which were built for Wii U), the Wave 1 textures are lower resolution.
A beginner-friendly stadium track originally from Mario Kart 7 . Mario Kart 8 Deluxe -NSP--Booster Course Wave 1...
Once the update is complete, you'll be able to enjoy the new tracks, items, and features that come with the Booster Course Wave 1 update. The Booster Course Pass tracks are heavily ported