Here is another one I will have a little fun with and probably get flamed, but here we go. I have been building and flying for over 35 years, control line, sail planes, 1/2 A thru gas rc (sport, scale and a few racers) and I have NEVER sealed a hinge line. I have only had a few incidends of flutter and that was due to either too large of a gap in the hinge line (building issue) and exceeding the airplane design speed. The throttle is used for that. Not to say it may not increase some efficiencies, but on a sport plane as the post started, would anyone really notice???????

John