This is an alternative proposal building on top of the Address Space Extension with Translation Map idea. See this for open questions.
One of the major issues identified is the inability to distinguish short (legacy) addresses from compressed addresses, and the resulting complexity of automatic translation.
In order to avoid this problem, we introduce a special contract type, called bridge contract, which announces itself being capable of interacting with the new address space, but is actually placed in the legacy address space (and has a short address). Other contracts in the legacy space can not interact with the new address space.
For the complete text see ASE with bridge-contracts - HackMD