Every Android or iOS App is a "should be fine" type of deal. So are lots of other things. If you are really worried I'm sure there's a sales person willing to take your call right now. It's not ideal, but honestly not that exceptional. And if push comes to shove you do have alternatives, you just need to sacrifice a bit of quality, maybe deployment complexity, and tune your prompts differently for one of the other models.
Do android and iOS stores have undisclosed fee structures for high revenue or high usage apps? I was under the impression that the fees were at least transparent, even if they do represent monopolistic rent seeking.