I also saw your latest videos, and to the question if i got in touch with him, well a little bit i guess, we started working on the next Challenge atleast, but even now there wasnt much progress done yet.
And well, when it comes to new ideas in parkours, especially when it comes to redstone related stuff, its sometimes just coming then because it been implemented to Minecraft at around that time.
For example Bonuschallenge 2 was built in 1.8, and in 1.7 the Setblock command had been implemented for the first time into Minecraft.
same for other things, in Challenge 24 you will for the first time jump on single glass panes, which is because that was built in 1.10 and before single glass panes still had that cross shape instead of just that 2x2 pixel from today.
So yea, Zone IV has the most interesting Challenges and ideas in it, but also one of the top 3 hardest Challenges which we built until now, too.
Overall you can say, that the fact we take our time building this map came with the nice possibility of a high variation of Designs because of new blocks, you more or less can see at which point which new blocks had been implemented into the game, when playing throught our map xD