I like sinew... I like sinew, a lot. Sinew is wonderful stuff. When I choose to sinew, it is a predetermined, planned part of the bow that I decide to make. I never use it as a "fix" or an "improvement" after the fact. (with the exception maybe for a sinew band-aid to hold down an unforeseen split or grain runoff). For myself, I believe that sinew should be a fore-thought, not an after-thought. But that's me.
With that being said, I am with the majority in that it won't help your cause. However, Nothing ventured, nothing gained. You seem to be seeking a nudge to go with it so, try it. Record a forced draw curve and some other stats maybe like max flight distance and chrono feet per second prior to adding sinew. Then record the same data elements after your sinew is on and cured. Then, you'll know for absolute certain gains vs. losses.