Any way to swap numbers between grandfathered plans on one account?

Hey all;

I have 2 separate lines on grandfathered plans — one is a SWAC line and one is an “on us” line (I actually have 6 lines but only 2 are involved here). I realize these plans are now pretty much locked in — but I’d like to see if there is any way to basically flip them… the number that is on the SWAC line gets flipped to the “On Us” plan and the number on the “On Us” plan goes to the SWAC line. No porting, no cancelling — just flipping the lines around so that the SWAC plan whose # is currently the 2nd eSIM in my phone that already has a decent data plan can instead be used as the main line in the standalone phone that currently is the On Us line — and the On Us line, which has no included international high speed roaming can be used as the 2nd ESIM line, where a data plan is really not even needed.

At this point I feel like I shouldn’t poke at anything and just keep it as-is — but if there is a straightforward option to do this, I’d like to.

Thanks!