Nadeo is asking for Stadium Chase TA maps from the community. By the way, it's a super fun mode released just last month. If you haven't played it yet, I recommend downloading the titlepack and trying it. Teams of two. And you can play even without opposing teams. Definitely you should check it out before mapping though, so you get an idea how the mode works.

Cerovan says:

Hello everyone,

As we said last week, we intend to update regularly the new Chase program on the Trackmania Channel. In this momentum we wish very much to integrate maps from the community. If your map is chosen, it will be played during the channel program.

You also will be featured on the forum, in the program’ changelog as well as on our social networks. \o/

Of course there are some guidelines to take into account:

• Your author time must be around 40s and 1min.
  
• Don't use (graphical) mods.
  
• No locators.
  
• Maps can give an incentive for long play but should remain accessible for newcomers.
  

It means you can use mixmap and embedded blocks too. You're not forced to create brand new maps, you can also simply rework your TimeAttack map(s) to make it playable in Chase (by moving and/or removing checkpoints for example).

I'll be reviewing the maps and giving you hints on how convert your maps if there is only few thing to change to make them great for the program.

Feel free to send the maps to cerovan@nadeo.com before next Wednesday (July 25th) 5PM CEST.

Have a great day!

Check this topic for more info: https://forum.maniaplanet.com/viewtopic.php?f=627&t=44311

So, it turns out this isn't a one time request. If you want to contribute maps anytime, send them in, and if accepted, they'll be added to the program periodically.