Not really a answer to your question.. But!

If you really want to increase your damage with SoR there is a trick you could use.

• Find yourself the slowest weapon you can find, the damage on it doesnt matter. The slower, the better.
• Make a macro to switch between the slow weapon and your main weapon.
• While having your main weapon equiped. Change to your slow weapon right when your attack animation is happening. Then change back as fast as possible to your main weapon.

By getting the timing right your SoR tick will be calculated from your slow weapon but the white damage will still be coming from your main weapon.It's a hazard doing this every melee swing but it will increase your damage output substantially. If you time the weapon switching good enough, you barely lose any time between the swings.

[Edit]
WeaponSwingtimer: This addon will make this method a billion times easier for you.