I quite like the idea of DLC, but in practice on the L1011 - it wasn't so useful. It was designed to prent big lift changes with small attitude changes on the approach. In practice, it was awkward, added weight, difficult to maintain and was eventually disabled by a lot of L1011 operators. As for the crews, you either loved it or hated it. And when activated, it made the landings somewhat firm in a lot of instances.
Also, have you thought about the effect of positioning the spoilers in the accelerated flow behind the props? If they're used in flight, I reckon you will get quite a bit of buffeting.