I mean, for example, to set a range for creating an address in a specific range, I want to create an address in 2 ^ 135 - 2 ^ 136 with a specific mask
For VanitySearch, I don't really see the interest of this options and it is a good way to see its funds stolen.
May be it can be useful for bitcrak, if you have detected a failure in a wallet pseudo random generator and you know more or less subspaces of generated key.