I agree with Tech Support, don't uninstall or upgrade for that matter. That version of SAS is certified with a certain version of the third-party product, but by uninstalling/upgrading now, you run a real risk of introducing all sorts of issues, which you will be fixing in the end.
We are mindful that the customer don't want unsupported software, but now is not the time to pull the plug. They will just have to live with the current version until the upgrade. The customer must also take responsibility for waiting so long before upgrading.