This is more about fairness in the community because digital is obviously faster than cartridge. It's unfair to the players who bought the cartridge because there is a limit to how fast you can speedrun the game.

I recently speedran 150 cc no items nitro tracks and i was playing on cartridge and i got 41:52 and i wonderd how peaple got 38 minutes. How many seconds faster is the digital version? It would be nice if we had a system where you put in the time and wich version of the game you where playing and then if you where playing on cartridge it lowers the time to fit the digital version or the same but the digital version gets a longer time to fit the cartridge version. Sorry for my bad English.

Here’s a good video by Gamexplain showing the difference between Cartridge and Digital, . 3 seconds of extra load time on MKS for cartridge is a pretty big disadvantage.

This would mostly depend on runners going through the extra mile of timing the loading sequences themselves, because:

1 - There's no IGT (In-Game Time). Thanks Nintendo for removing the race timer in a racing game.

2 - There's no auto-splitter for this game. Console games are hard to set up for these as far as I've heard. And as far as manual input solutions go, the ones I've seen have been fairly convoluted.

3 - While loading times have been timed before, giving us a reference of how much time difference lies between Cartridge and Digital, the loading times aren't consistent. So while one can know by average that a 48 track run on Cartridge is around 60 seconds slower than Digital, the small variations per load make it hard to say that it will always be a 60 second difference.

4 - Also to add to the above, the Digital version is further segmented into internal memory and SD card storage. The game loads a bit slower when loaded from a SD card, making any timing references even more unreliable.

For now, if the version difference is that much of a concern I'd suggest using the Filter button on the top right of the leaderboard, and use it to visualize Cartridge or Digital runs according to preference.

Also, I wouldn't be too concerned about the time difference between Cartridge and Digital unless your runs are getting to a high enough level where the time difference REALLY starts to matter. In most cases playing via the cartridge is fine enough.

Previous discussion thread with more relevant info: https://www.speedrun.com/mk8dx/thread/m129v