As an architect, my first thought would be to decline the commission. 20,000 courses worldwide, 360,000 holes, what's one more or less featureless hole?
Barring that, Michael H suggestion is the most practical, build up two small berms (not high enough to make them blind, no one likes that) which saves drainage costs. But rather than design it to propel the ball off the back of the green, think of it as creating an alternate way to reach the green with some run out, perhaps a better one than flying it in to the small saucer, which I imagine to be slightly crowned, since most are.