Simple answer is no. It wouldn't have been possible.
Ask chuckie or adsun about it. They've driven the map before anti-cut scenery started to be added. I'm sure they will tell you that it's very easy to take the wrong way in some parts.
Keep in mind that when you built your single part... it was obvious to take a turn on the outside corners of the track because the alternative was flying off into nothingness. Now that your track part is combined into the bigger track... you often see track ahead of you and might jump into another person's part instead of taking the turn on your track part. So areas like that have had to be blocked off.
Also, I'm keenly aware of the fact that many people simply lack any sort of intuition when it comes to finding the track route. If there's a wrong way to go, they'll inevitably take it and not think twice about it. So I'm trying to make it possible for even these type of people to finish the track, because they deserve to have fun too. It's not their fault that they lack this intuition.
Areas of your track that might have been bright enough when your track was exposed to light on all sides are often too dark now that they are surrounded by other towers. So lighting has to be added in those cases.
I understand the viewpoint of trying to do as much as possible with the vanilla editor. Most of my own tracks were only made with the vanilla editor. And I think blockmixing can be used as a crutch when simpler, and often more beautiful, solutions should try to be found. It's been a hotly debated topic for years in TM. Many are against mixing, while others embrace it. I try to find some middle ground and only use it when necessary.
This track is a special case where we are very limited on space. It's a situation where I believe it's really necessary.
We really don't want to risk someone going the wrong way. Of course it's not a big deal to leave open areas on a 45 second track and let people discover the route over the course of a few runs. But in a 45 minute track it could be disastrous if someone takes one wrong turn and misses CPs. They're not likely to try it again if that happened. It could easily ruin a person's opinion of this project. And I really don't want that to happen. I'm sure none of you do either.
So that's the main reason why I'm implementing some mixing into the track. Blockmixing is a tool to accomplish an end result, that of a fun track that everyone can finish... well... if they have the patience and tenacity to drive for 45 minutes straight.