You cannot "void" your warranty except by fraud or other criminal activity. Installing something aftermarket won't void a warranty. In the case of installing something to the roof, it won't void the warranty, but if you drilled holes in the roof to install it, and the roof leaked through those holes, then damage associated would not be "covered" under warranty.
It's a big distinction between voiding and impacting coverage in a very specific area.
People with goods under warranty tend to be very afraid if doing "anything" lest they void their warranty. Please don't be afraid. Manufacturers can only deny claims for repair if the modification you did directly affected the part you were trying to claim. For instance, if your torsion axles failed and required replacement under warranty, the manufacturer would not be able to claim that the addition of a wind control device led to torsion axle failure. If the bubble window leaked, this too would not have anything to do with your wind Cheeta. So don't worry so much about voiding warranties.
As to the wind Cheeta itself, I've seen many install this and similar devices when they live in windy or open geographies.. And many of these are intended to only really protect during the deployment and takedown phase. A very short period of time.
Where we live in the northeast, there's too many trees and not enough tornado winds to make us consider one. Once the roof is up the cam-lock system is sufficiently secure in my opinion to withstand very high winds and if conditions ere truly extreme (nor'easter, hurricane) then I would not be waiting it out in a lightweight camper anyway and it would be down and put away...
So I think the choice to get a wind kit should be based as least in part on, your geography and typical weather patterns and you ability and strength to raise and lower the roof efficiently and with control without an extra aid device.