The intelligence level of SQL Optimizer maybe set too high. Try lowering it in order for SQL Optimizer to apply less hints and permutations on SQL statement.
Consider splitting the rewrite and alternatives execution operations in 2. i.e. Instead of using Auto-optimize, run rewrite first (tuning fork) and then click Test Run. Test Run can be further split by doing Test Run - Selected.
Instead of using the default settings for the Test Run, you can customize the settings by clicking on the link bottom left.
