It is really important to know if the air follows a straight line still or it is being diffused (that’s a result of bad performance), they need to know about the vibrations, the speed and the pressure and the direction the air is following. And it’s needed to know how is it going to affect the back end of the car, when especially the new fins are used it’s vital to know that data for knowing their success on the design or total mistake.

However it is a kind of periscope to catch some important numbers, but not to see anything far away

About the fin, they’re following the development that the average from the cars is following. This is the most realistic for a little team, shorting months of investigation and design, by getting a borrowed idea and applies it to their own solution and look if it works well.
Well, square shapes were used when motors were bigger and more powerful, needed lots of cooling, nowadays teams can cut more their shapes because the V8 limited to 19000rpm don’t need that amount of cooling, and try to better the aerodynamically shape.
Seems Force India, needs that over-cooling (could be possible because they want to be reliable) or have years lag in their chassis design (surly, it is it). Anyway, team Force India is some kind of rising F1 team, the new spare parts will come soon I guess, that’s not the old Pacific Racing…. And their owner has got high expectations!!