Yes, V1.8 still runs on XP11, with some limitations. However, consider that X-Plane 11 is an End-of-Life platform, no updates will be made to it by the vendor (Laminar), no bug fixes, no new features, nothing. The CL650 will stay compatible where possible, but do not expect it to be fully featured at the level of X-Plane 12 version. E.g. There will never be a functional weather radar for XP11. If you computer has the performance for XP12 it's long passed time to move on from 11.