Although it might not be mentioned elsewhere, tints normally does not warranty heat demisters of cars unless you negotiated in advance. Even if stated on my warranty, I will dismissed it as it is sort of like taken for granted heat demister working is on our own cost.

Normally installing would not cause any issue BUT removing tints (under or after warranty) might damage the demister. Normally makan sendiri when that happened, either change the RWS on your own or just live with no heat working heat demister.