I understand perfectly what you’re saying but if you think about it, Preform did not have even basic functionality like mirroring until just a couple of iterations ago.
The ability to add a hole is a much more complex undertaking, because it’s not something as simple as adding a hole, it first needs to hollow out the solid to a predefined, or user defined, wall thickness, then add the drain hole.
But you’re right, considering how one of the selling points of the FormLabs printers is the ease of use and sophistication, one would expect these features to be part of such a package.
Other 3rd party software like ChiTu Box, does all this and does it well. Perhaps Formlabs should take a look at Chitu and see if they can work out a licensing deal to include some of these features in their upcoming Preform releases.