So lets say that we dont have a gauge for alUSD.
People could swap alUSD for DAI and provide to any gauge and double dip just as much. So long as you can borrow against a curve position you can leverage farm.
It wont be long until you can borrow against convex positions. This proposal does not accomplish anything regarding double dipping because the same amount of CRV rewards are released, and it doesn’t matter which pool is getting them as debt can be converted into any qualifying pools assets.