How hard will it be to add features depends on the way it's architected, but the real issue is complexity. After you add other distributions, bounds, etc. the user would have to figure out what are the right choices for his specific situation and that's a set of non-trivial decisions.

Besides, one of the reasons people like normal distributions is that they are nicely tractable. If you want to, say, add two it's easy to do. But once you go to even slightly complicated things like truncated normals, a lot of operations do not have analytical solutions and you need to do stuff numerically and that becomes... complex and slow.