okay, see, lets just use some common sense here:
a turbo timer is an electronic device to keep the ignition on for a set amount of time. just because it has "turbo" in the name, doesn't mean it connects to the turbo, or any mechanical parts whatsoever.
by your statement of: "mods that have any effect on mech parts and or their opperation" , puts the boost gauge itself as more of a warranty voider than the turbo timer, as the gauge has to tap into some kind of manifold pressure line, which i guess, in some wierd far out way, could potentially damage something mechanically (how i dont know).
maybe if mazda is selling turbo cars, they should at least teach thier employees what a turbo timer is.
the reason i sound harsh is because you are here, giving information that a turbo timer is a mechanical part that will void your warranty, when its totally not true and doesnt even make sense based on the definition of a turbo timer. if you dont know what it is, dont assume it will void your warranty.
im also slightly irked that most dealerships will never admit they dont know something, they will practically make s*** up so that they dont look stupid. ive had my car for service for the subwoofer before, (which my allmighty turbo timer somehow blew

) and the ******* pricks put down "Modifications to turbo wiring". WHAT TURBO WIRING. there are no WIRES that go to a turbo. DO YOU EVEN KNOW WHAT A TURBO IS?! (jerkit)