The claims should be not showed with F4 at nights, because it is a very disadvantage against the defender of the claims.
The enemies can see the defenders in the claims, but the defenders cant see the attacker outside the claim. That is definitly not intended by the developer.
Suggestion:
It should be only useable in the own claim to see their own borders
or
It should be only useable for some seconds and than be on cooldown to not abuse that mechanic in PvP at nights.