If you call a premature election, you're treating people differently than what they normally have a right to expect, which is a fixed election date. It does seem to me it goes with the territory.
I would prefer the permanent list, but if there are serious problems with that—this is not my expertise—the alternative of a longer period is certainly the second best. The current one in which everyone is having to produce the documentation after the writ is called, I haven't seen anybody defend that. I can't understand how it could be defended.