Supply Challenge broken?

[running_bird]

Hi there,
I really did play this game a lot. Had my mega base and stopped playing for a while.
Just wanted to play the game again from scratch and figured i can redo the "Supply challenge" again.
I am using version 1.1.33 (build 58442)
I failed multiple times really hard. Always in level 11 where you need fast belts because I am not able to research them in time.
In my last try I had like 5 labs running at level 10 and 10 in level 11.
But they were too slow to research fast belts.

I am not sure if I am doing something completely wrong or if balancing made this scenario (especially level 11) extremely difficult.

Maybe I am just stupid. But right now I think "Supply challenge" is extremly difficult. Although I think it may be a nice challange for existing players because I have the feeling it is doable:D