Like the guys have said, if you have already pushed the wood to the limit, you can't get any more out, trust me I'm sure we've all tried.
Typically what happens is you steam in some recurve at the tips, which either pulls back out again, or the limbs take more set so that the tips end up back where they were.
OK theoretically that may give you a tad more speed due to change of string angle, but it won't do much.
What it will do is give you some good practice at tip bending, and give you a good feel for that particular timber. It will also keep you out from under the wife's feet
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Del