I propose to remove it.CRF wrote:Once the effects of an environment card have been applied to a target during a given
movement/hazard phase, that effect is not applied again to that target during the
current turn.
It does not regulate anything. It does not solve any problem. It introduces a confusion.
Effects of cards in play that are applied to some objects are applied as results of actions caused by passive condition. Once per occurrence of the condition. Whether the card is an environment card or not. There are no essential differences between returning a company in result action from Snowstorm and returning a company in result action from The Way is Shut.
Effects or short-events are either applied immediately, or not applied at all, i.e. a target or objects on which the card operates are under effect, usually by some period, e.g. until end of turn.
Other effects of environment cards in play are not applied at all.They last as long the card is in play. E.g. if Fell Winter is in play each Border Hold has an additional AA of Wolves. Bree is normally Border Hold, so it has the Wolves AA, if it will become Ruins and Lairs it will lose it, but if it will become again Border Hold (even during the same turn), e.g. because Nature's Revenge has been discarded, it will have the AA again.
If a site that satisfies the conditions of tapping action from Long Winter will be tapped by the action (or by anything else), then, if it will become untapped, it will not be a new occurrence of that triggers the tapping action from Long Winter.
Unless the counter of occurrences of the passive conditions will be reset at the end of turn. But the quoted rule does not say that it is reset, it does not imply that it is reset, it at best suggests such possibility.