I was exploring the canyon platform source code to find exactly what causes this and just ended up to rewriting the ruleset to transform the platform gamemode into a normal race mode again, which I doubt is the most efficient way.

I think it could be handy for title packs even though it let's you skip medal requirements of maps.
EDIT:
So here's the result of me messing around, it's a demo campaign of Canyon with the option to go to the next map directly. It's not as good as I would've liked.
- You can't select ghosts.
- You can straight up skip medal requirements for the next map. (which can cause buggy behavior!)
- Some glitchyness in the intro and outro sequences.
Race Next Map
For title pack creators
It's pretty easy to use this in your titlepacks.
- Place RaceSolo.Script.txt in Scripts/Modes/TrackMania
- Place TMRace.Script.txt in Scripts/Libs/TrackMania.
- In title pack editor, under solo, choose RaceSolo.Script.txt as your mode.