The moderators of https://www.speedrun.com/Van10 (myself included) asked the Supermod of the series to create Category Extensions of the game. The supermod Astr0 gave us https://www.speedrun.com/ce , but we don't know how to link it on the main game as "category extensions". Astr0 seems lost as well.

What do?

You need to add a Category Extention Game Type with the base game set to that main game.

Only site staff can edit the game types so you'd need to submit a support ticket (Help > New ticket)

1. Press New ticket
2. Choose "Change an existing game or series"
3. Press Next
4. Choose "Change the type of an existing game"
5. Press Next
6. Choose "Mario & Sonic at the Olympic Winter Games (DS)" as the Game
7. Tick the Category Extention game type
8. Choose "Mario & Sonic at the Olympic Winter Games (DS) Category Extensions" as the base game
9. Press Submit request

... Why are you making the Category Extensions board the base game?

Shouldn't it be the other way around?

Yeah you're correct it should be the other way😭