Used to be people always vaped in a limited range of power, but now it's all over the place. Some people use a lot of power, some people use a moderate amount of power. Even if you change out the fuse for something with a higher rating, you can easily get a false trip if you use a lot of power. If you don't use a lot of power, it will do the job for you. You might be able to stack a couple three fuses on those pads to get the rating up high enough for a higher power device. No issue in doing that other than the difficulty in soldering small parts.
Oh, SMD style PTC fuses typically have a 6V rating so as long as you are using a single cell, you're okay. If you were to use a stacked cell configuration, voltage would exceed the rating. It would only be an issue if the fuses trip, could burn them out. Otherwise voltage is only limited by the fuse's dielectric tolerance which is way higher than what you would ever vape with. So you could vape with stacked cells using that fuse, but it might overheat if it suffers a short circuit condition for too long a period.