First off, cool idea! I like the track, its marked out well and the unique signage is both cute and functional. Plus the unique setting grabbed my attention immediately so kudos for that.
2 things for you to look at though:
Getting Orbi'd over here, or just an extremely poor driving choice can get you stuck between these chairs and the wall, requiring a respawn console command to get out, which not every netgame player will be aware of.
You can just linedef ride up this little shortcut ramp since the offroad sectors are too small to slow you at speed. This can easily be remedied by using a control sector with linedef 8, checking touching sector edge, then applying that linedefs tag to those sectors. While I missed it during gif recording time, doing this usually results in snagging that item box which lets you mash a free item before the actual set which can be fairly powerful and assists front runners.
Edit: And on further examination, checkpoint 2 doesn't register at all. But thats the only broken checkpoint I found. But since you can pass its waypoint area it causes position shuffling at the start of the track which can disorient people.