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Full backwards compatibility (in particular, binary compatibility) will be hard to achieve. The current approach is to create a set of adapter classes and a backwards compatibility library (BCL) that would satisfy overwhelming majority of the requirements, but leave the hardest cases for individual consideration.
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To define specific requirements, we need to identify specific classes that should be included in the BCL. The initial approach is to use API scanning tools on custom channels of current uP2 installations.
As a second stage, we would like to identify a specific set of channels that community deems necessary to support at the time of release. We encourage everyone to contribute to the required channel support effort.
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