haenry says:
There will be MTCs with custom titlepacks in the future for sure.
However, the server is indeed one good reason. Another reason is that this current theme gets complicated a lot with many custom objects in Titlepacks.

I guess it makes sense.

Some stupid questions:
a) do multilap maps count?
b) are custom signs allowed? (or do we need to use only Nadeo signs/panels)

Is there a minimum amount of time that can be spent on a surface?

Road 5s -> arena platform 1s -> Road 5s legal?

The different physics were just an example. In Canyon the wide red road (GP) and the small road have the same physics, but are different road types non the less.
On the other hand, if the physics of two blocks are different (normal road piece and dirt road piece in stadium), then they are different surfaces.
One thing implies the other, but not the other way around:
different physics material -> different surface
different surface -/> different physics material

And with "physics" I mean the material properties of the surface. So it doesn't matter if downhill/uphill, etc.

You can submit multilap maps and you can use whatever signs you want, ranig

nope FillInTheBlank, the minimal time doesn't matter, since it is about changes. But I can say that 5sec platform -> 0.5sec road -> 5sec platform -> 0.5sec road ->5sec platform.... won't do any good

Thanks for clearing that up haenry! It makes a lot more sense now :

is this also counted as a surface? if so I might have a few idea's

What else should it be, lolig?

Is it allowed to mix different surfaces to create a new one? Like here in the pictures:

No Beatinfected, that would allow to mix surfaces everywhere with custom objects and thus ruin the challenge

I think most people are over-complicating things, the spirit of the theme is clearly to promote block variety above all else, I think builders should think about that instead of the minutiae of what counts as a surface or not.