The security of the Augur v2 Oracle was designed to be independent of trading, so long as sufficient trading fees can be extracted such that the total REP market cap grows to be able to maintain security of the oracle via Augur's forking mechanism. Because of this design decision it is possible to move Augur v2 Trading off of Layer 1 (ethereum) and on to any other plaform with the constraint that the assets used for trading must be locked up on ethereum when participating.
Since releasing Augur v2 work has been done to implement support for multiple collateral types in Augur. This feature is referred to as "ParaAugur", meaning Parallel Augur. This implementation allows multiple trading implementations, collateralized in arbitrary tokens, to pool their Open Interest such that the security guarantees above remain true. This opens the opportunity for side-chains to interact with a specific collateralization of Augur depending on their use case, and also opens to the