Hi Nial,
Yes it has a Purpose. One is to prove that a good set up and design eliminates the need for a flair. The flair only reduces rudder power. and will give terrible mixes under load in our high demand maneuvers. The other I can`t disclose.
We must remember that the ability for great stability and Agility comes from the Wings. Everything else is an aid to those wings. Fin/Rudder Stabs, Fuse , Power ECT.Learning how to compartmentalize the Job of each part of the airplane and tune them to perform ONLY their job will eliminate most if not all aids. and guide the designer in the right direction for improvements. If you can`t find the boundaries of improvements or failure How can you really improve the design? you won`t find that by just slapping stuff on.

It`s like my Triangulation trimming guide. http://ckaero.net/guides.php Consider it a puzzle. All the pieces are there to make the picture. I have the boundaries, the like colors, the middle section and the main part of the picture there in the box. If you try to put a boundary in the middle part ,or put two pieces not of the same color together, it won`t complete the picture. But when all the pieces are in place , Only then can you enjoy the Picture and all those little pieces start making sense.

I`m not saying all add on`s are bad, some work well I even use some But, Most cause twice as many problems as they fix. Starting with a good foundation of power and purity in design setup will do wonders for high demand maneuvers such as the new schedules are demanding.

I know there is more than one way to skin a cat But here lately, I think the Knife has become a little dull
Bryan