Correct... Best Plan, in my opinion, just tracks are good for now.
Especially with the new one piece roof without any screws to indicate where the roof ribs are located, which would make the DIY, I mentioned, much harder. And, how many years are you going to keep the camper? The next owner might thank you for installing them at the build time and you could probably recoup a fair portion of the associated costs. These campers sure hold their value over time.
FWC should be able to trim the length of the track to fit as the end caps are independent parts and the track is just a track.
The tracks options available are endless as both Yakima and Thule roof rack systems can fit with the Yakima tracks.
I didn't get the FWC/ATC factory aluminium rack thing, as it didn't seem to fit my needs, so, I can't speak with any personal knowledge.