With age I’ve really pivoted on when to zipper merge. It used to be”merge early to be polite”, but now I’m firmly in the camp of “If everyone merges at the end, then it is perfectly equitable to everyone.”
It’s the people who merge early who cause the unnecessary disparity. At least, when one lane is ending this is true.
Me and my best friend played halfling twin brawlers one time who would use each other as improvised weapons and crawl in big guys Shadow if the Colossus style. It was the most fun thing ever, but the DM turned out to be the “if someone doesn’t lose a limb during every encounter I have failed” kind of DM so it didn’t last long.