Here’s a mindset for this situation.
We all know people who are not really interested in an even conversation. In fact it is not a conversation. What usually happens is that the point of the story gets concealed and there are plenty of details that serve to confuse. It’s a confusing tactic be it conscious or not.
So you would need to focus on certain things:
1. Don’t get confused
The idea is to get what they want to say and then focus on that and not focus on all the meaningless details. You can picture their point hovering above their head and focus on that, you already got it, now you’re just waiting. This way you communicate without words that you are waiting for them to get to the point and you are polite though. It’s not needed to take it personal cause it would feed the dynamic. Sometimes we act dumb cause we don’t want to be impolite. So again when you focus on their point the words won’t confuse you. Other times the point is hard or impossible to get but then you could ask. If they act as if you were rude ..but this gets clear in the next point.
As for the point hovering over their head -“thing”, it’s still applicable just put a “?” in that space 😉 and dismiss the details, you could picture they move around you out of the window or such. It’s all about focus of attention/energy which you especially don’t want to put on yourself at least in a critical way or something among those lines if you know what i mean.
2. Turn it around
You could call it reverse gaslighting but it’s not really an aggressive act. They pretend to not intentionally come to the point. Well you can pretend that they struggle getting to the point and you help them out so they don’t have to talk so much. That’s what naturally would happen if it’s an even conversation between good friends and the other side would be thankful you let them know that you got it. People who talk at you though cannot relate mostly out of fear actually which helps to not take it personal although the theme of control is there too, but you can also not take this personal.
So let’s say you interrupt and let the person know you got their point – and it’s important to not do this aggressively, because you would only feed into the dynamic – they may get annoyed about it and villify you and if you took it personal in advance they will so to speak have a reason in their book be it un- or consciously. This may then cause guilt or something like that or it may escalate the situation even which may be something you do not want to bother with. Sure, if you want to pick a fight then why not but maybe you don’t want that.
But if you “act” as if you helped them out they may still act as if you were rude but you can then keep it up and find ways to communicate your reality such as: “Didn’t you want me to get your point?”