Wallrunner says:
Of course it is. The point is, that i play a map, that has been built in trackmania before the titlepack even existed. But the replay i drove, has been done on a server with the titlepack on it. You can watch the replay in both, the main gae and the titlepack, but you can't upload it on tmx, because the server had the titlepack on it. It'S kinda hard to explain to be honest.
The main reason it's not allowed is because you
cannot load it in the original titlepack. I don't know for sure if this has changed with mp4 though, iirc it hasn't changed. (secondary reason is physics, but that can be solved in another way)
If it works without having the original pack installed (or at least loaded), it's worth reconsidering this in my eyes.
I know it's really annoying, but ensuring people can actually easily view replays has a lot of weight. It's sort of a core flaw with the titlepack system.