In the long run, Bitshares 2 will not be able to compete with BEOS. I think it would be illusory to run BTS2 in parallel with BEOS. A DEX needs a lot of liquidity to take-off and there is no point to split it between two clones, BEOS having a total technological advantage. I like your BEOS idea A LOT ! From my point of view, I would prefer to do a pitch fork from BTS2 to BEOS. Imagine, an unlimited tx/sec low latency DEX with no transaction fees (no need for BEOS block producers). The scarcity (value) of Bitshares would result from using it as collateral for BitAssets (like HERO).
RE: BEOS - Alternative proposal for Bitshares 3.0