I have lb-local set to enable, but locally generated traffic doesn't follow the load-balance rules, and instead uses the main routing tables.
The problem with setting distances on the main routing tables to 0.0.0.0/0 is that the only time the route with the higher distance is used is when the route with the lower distance's interface is either physically unplugged or manually disabled. If traffic is being dropped upstream but the interface still remains enabled, the failure is detected by load-balance's route-test, and failover happens, but locally generated traffic still goes out the route with the lower distance, because that route is still in the FIB, I suppose.