Just wanted to check my theory, yes it works. Made a quick POV
It actually works in a kinda realistic way too, as the coaster gained prestige due to longer track (as it's the same track laid twice), so it does actually represent a 'better ride' now. I guess in campaign mode that would allow you to charge more and get higher ratings, so it works from a cash flow perspective too. Bit fiddly, but it's not that hard and it's even possible to use smoothing and make adjustments to both circuits of track and keep them aligned as one - so long as you replicate your actions when editing both tracks.
No reason this can't be used with more than 2 circuits and even multiple trains if it's set up carefully.
https://youtu.be/l4O7yScxSEo