don't see any problem there.
Maybe it would make sense to replace unlimited by an defined number to avoid "Monopo(o)ls".
(don't know how to do in open source SW)
Big pools could become bigger and bigger due to more frequently forging.
This allure (more accounts => more frequently forging) + self gaining...
Node owners must be allowed to configure it to any number, 'unlimited' or '0' or '42' by default, I don't care. It'll be a nice parameter to have, that's all.
The way it's set up now is 'unlimited', because there is no configurable restriction at all.