Sounds like a dope category but I have an idea of how to more easily verify the run, if you talk to Toadette in the Mushroom Kingdom there is an achievement related to collecting checkpoint flags, I believe there are 85 checkpoints total in the game so if the Toadette counter is at 85 then you should have collected every checkpoint flag
I believe some checkpoints get replaced by the Odyssey, my counter is at 85 and so is most peoples counters when I googled it
If you need help I'm available, I made a spreadsheet myself of potential routes for some kingdoms I also did a map with all the Checkpoints on it for each kingdom
Let's not spam people's notifications, DM me on Discord and I'll try to help, Discord is Smoothie#8877 (If you don't have Discord then idk what to do)
Just join the SMO speedrunning Discord while you're at it. Link is at the left column on the main board
@FroZen_WaTer_99 in my opinion, you forgot one in mushroom kingdom. Im not 100% sure, but I mean, I think there are more than 4 checkpoints in mushroom kingdom lmao