The town encasement rule is meant to make towns "reasonable to siege", however there is not much info in it to explain what reasonable means. People so far have read and understood the rule as "you need 50% / 2 sides open to siege".
In reality all wars have been fought via a single siege base and have been fair so far. Due to how the siege war works, no one will make 2 siege bases opposite to each other since the attack is focused on the side of the banner and anything on the other sides is meaningless. Therefore I feel like even if only one side is open that its still reasonable to siege. Some places like EU already have scuffed sides to attack so its not like it changes much for them
Now revolt wise, I think everyone can agree that some banner placements of defenders are unwinnable for attackers. This being placing fully opposite to their siege base. Due to this it should be changed to either one of the two:
"I like placing opposite to their siege base" - In this case given that no one will fight in a that much unfair banner, might as well make siege immunity last 4 weeks but make it so they are auto released after 2 meaning nothing changes apart from saving people time from capping the banner as defenders of the town
"I think this is bs" - Make it so that you can only place it close to an enemy town. This would at least make it PLAYABLE for attackers to participate at bare minimum. This only applies to how the game is played, not the outcome of it. If the server wishes to avoid people being perma occupied they can give them some kind of lose streak benefits such as earning more points. That would give them an advantage in terms of outcome but not change the gameplay of it. Basically the point is for the banner to at least be contestable, everything else is up for discussion