It's not free to create the mechanism to provide the 12.x.x software that was current when an individual's subscription lapsed. The cost of doing so could be significant for Xara. There's no 'easy' about it.
In terms of entitlement, user's entitlement is what they agree to at the time the subscription starts, which seems to be a 12.0 disc, and no access to updates to 12.0 after the subscription lapses.
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