Limit updates by major version

I'd like to implement a mechanism where users pay for major versions of my software and receive all updates for that version for free. I have an eCommerce store where users buy my software and that's where they'd pay for and receive the current major version.

What I'd like is for wyUpdate to update all users of 1.x to the latest 1.y build, all users of 2.x to the latest 2.y build etc. That is, I don't want users of version 1 receiving any updates to version 2 and so on.

Is this possible with wyBuild and wyUpdate, without having to create multiple update packages?

Many thanks again for the great software!