I, on the other hand, doubt that it can be read once optimised. I don’t believe forward compatibility is something that software companies worry about these days. I.e. being able to read file formats (or databases in this case) with the version previous to the one that had the enhancement.
Then again, it should be rather easy to test, no?
On a side note. I rented a DDJ-SX for the weekend gig I have coming up and am playing around with Serato. Very curious to see how that goes (don’t worry, I still have my full Cross install on the MBP just in case 🙂 ).