It might sound obvious enough from an idea perspective, but that's just one out of many reasons for or against doing it.
For example, you've perceived an opportunity; but how often would you actually make use of it personally? Is this just one board you're working on that would benefit? How many others would, then? What about other customers? Finally, how often will it show up in the total production flow at the fab itself, and is that enough to justify adding the process step?
But you don't really know. Manufacturers even, don't really know -- there's a bit of a chicken-egg problem, no one orders it because no one offers it. At least at such a price point. Laziness being the default, it would seem an unlikely step to take -- that's a lot of capital cost, for something extremely price sensitive already, and of dubious value.
If an illustrative example can be made by moderately priced fabs for example, maybe the cheaper ones would consider adopting the process -- they aren't going to do anything that isn't well proven and cost effective -- but here again, very few are doing it, so it seems to be unprofitable. Maybe again the problem is it's a nonstandard option, so, a cost adder, its popularity artificially suppressed from the actual equilibrium price, if only it were to became the norm -- but so it goes.
Tim