I tested doing that and the Distributions are there and the data passes DIC so all seems OK. Perhaps, when Softrak ships a new version, they should test-convert data from each previous version and have a checklist of all supporting files to check and screens to review.
I think as a best practice going forward, when I have to convert from Plus or a very old Adagio version, I will step the upgrade through older versions through 9.2 rather than going to the latest version.