Have a Keep Fight task separate from the current realm task. The only objective is to fight over keeps in a frontier.
Keep Task - Fight over Keeps in an entire Frontier. That is the whole task. Keep task is in Albion and you earn RP for holding and taking keeps in Hadrian's, Pennine, Sauvage, and Snowdonia. The realm that holds the most keeps for the longest during the task earns a bonus RP reward. Scoreboard showing what realm controls each keep and for how long so you can tell who is winning.
Keep Task - Fight over Keeps in an entire Frontier. That is the whole task. Keep task is in Albion and you earn RP for holding and taking keeps in Hadrian's, Pennine, Sauvage, and Snowdonia. The realm that holds the most keeps for the longest during the task earns a bonus RP reward. Scoreboard showing what realm controls each keep and for how long so you can tell who is winning.