Poland could be used as a "torpedo" to create a breach in the EU in a right moment.
I think you are giving Boris too much credit. At the moment he's throwing everything at the wall, hoping something will stick. However, there is really no deeper strategy to his actions than to just preserve his grip on power for a few more weeks, or months. That's really all that defines him as a politician, and is why nobody should really worry about Boris accomplishing anything.
I think this is why Germany and France are largely ignoring the strange proposals that come out of his office almost weekly at this point. Usually they would be irritated that the UK is proposing an alliance structure that is parallel to the EU (Boris's little Intermarium plan), and would thus have an erosive effect on the Union itself. However, because they are dealing with Boris, and because they understand that even Poland and Ukraine are not stupid enough to trade the EU for a dying UK - they are just content to sit back and watch him embarrass himself.
This week, likely, there will be a vote of no confidence to Boris as PM, because enough rebel Tory votes have been gathered. Some idiot ministers and MPs are still saying it's wrong to remove him while the war in Ukraine continues, but it seems they are now in a minority.
The problem is that the person most likely to replace Boris, Jeremy Hunt, is potentially even more incompetent than BJ. I know this sounds hard to believe... but it seems to be the case.
Bottom line: Anglos used to be the masters at playing countries off each other and coming out dry. Now they're just sort of bouncing around, like a plastic bag in the wind - when their attention does become focused briefly, it's on harassing French fishermen or making life difficult for Irish business owners.