Ok there is no easy fix on Rare's end and they have a lot of stuff to keep up with so I imagine that they prob won't mess with Hg mechanics anytime soon. I have thousands of levels in hg so I understand where you are coming from with your anger about runners but there is a guaranteed way to deal with them. 1st thing is be patient, remember they love to see you get angry, nothing you say will make them re-think what they are doing. I recommend saying nothing, stay concentrated on all the kind words you are gonna talk when you finally get them. Try playing music, joking with your duo, think about your fellow hg players who are getting blessed because you are keeping the nuisance out of their games, just stay positive it will prevent you from messing up and giving them the win they are desperate for. Remember they are desperate, one to get your reaction, and two to win the game. I have found these guys get hilariously angry when you keep chasing them without any reaction, ESPECIALLY when you win. The mindset that wins these fights is that you are gonna spend as much time as possible, if you have two hours you are gonna spend all two of those god given hours making these pathetic players day so much worse. You are gonna chase them until they are forced to fight you, then you will beat the forums restricted language out of them until they run off again, then you will chase them until eventually you get them where they can't go anywhere but under the water.
Now the mechanics of fighting these guys is actually pretty straight-forward. If they board use everything in your tool box, throw blunder bombs and double guard with blunderbuss (have one player by the wheel-anch to watch top ladder and one guy stand by cannonball barrel and stand on the side of the boat to knock them off). If they get on don't get stressed sometimes they are better just try to break the camp and use the time to practice shooting some guns. If you get bored scuttle, remember rule 1 don't let them get too you. Now their weakness is that they are allergic to naval, they can't tank, no game sense and swabbie cannons, they can only run off, so you want to close the distance with your ship. If they are sailing straight follow them, try to speed up with your sail but IMPORTANLY try to predict the way they will turn in (they will have to in order to board or at least get away from the boundary). Once you see them turn cut in on them, keep their boat in-between you and the edge of the circle like you are slowly squeezing them in (remember to look for merms and laugh as they desperately try to avoid you). If they are keeping their boat in a spin this is even easier because you can easily catch up and put your boat right in front of them. (super easy for solo)
Once you have caught up now you need to relax, wait until you know that you are confident and send some cannons to test the arch then trust your chains. It's important to not get in your head about missing shots or letting them getting away, because I can guarantee you they are fuming right now. Don't waste sups if they are too far. Once you get their mast down they will catch so don't send a boarder. (helm: keep your cannon's angle and make sure that they are close enough to keep demasting them, also if your confident try raise sail to get the other guys to nose right in) (Cannon: goal one keep that mast chopped, so send chains and aim cannons at the top deck to get a cannon chop. When you know you hit their mast again spread your shots out, so shoot a few front holes, then a few back holes) Also use whatever you want i.e curseballs, bonecallers, running means no mercy. Once their mast full drops you have pretty much won, they will often give up and if they don't just keep spreading holes and sending boarders till they sink. It's long but trust me its worth it. Onetime I was playing on Christmas morning when these French players vpned across the world just to mess with NA players by running while watching a tv show. They ran for an hour and a half we kept chasing all while they were messaging us, we never got angry and eventually crushed them They cried in my dms for an hour.