and it would make reversals very necessarily limited, and would require more tactics and time, which is why I think it's good

If you make reversals "necessarily limited" that does not increase the requirement of tactics and strategy, it decreases it. Capping should be high risk high reward and it's perfectly done with the reversal mechanic, 7 minutes is already a decent amount of time where atleast one person has to stay on the banner, it does not need to be increased. Knockback swords, cannons and other methods can be used to easily and effectively push enemies off the banner if you know how to use it well

bro the 7 min reversals are very hard to win in proper sieges, take in mind a fire rez is 8 mins, and each strength and speed pot is 1:30 x 4 = 5:20 mins, you dont even have enough pots to last that much of pvp time, capping those 7 mins in is hard as fuck. dont make suggestions without taking into account of what you'll do if you were on the opp side