As I said, there are no seasons in the challenges. If the points reward was too high, then a new player could never reach the top. (unless top players get inactive)
Btw, can I steal the trophy sending a late replay? Like for this challenge, there is a custom trophy, I like it.
Challenges have 2 kind of trophies:
1. Challenge trophy
2. Map trophy
You can steal a map trophy by holding the best record on that map but you can't steal a challenge trophy if it has expired.
For example in this challenge oldsock has the challenge trophy even though Mablak holds the first place. Mablak doesn't even have the silver or bronze medal for the challenge. (since he didn't take part in the active challenge)
But Mablak holds the gold "map medal".