Those are pretty interesting concepts. They might even be expanded upon in multiple ways simply by allowing more bladers into the mix per team. I think for both concepts, a bit of the concept of splatoon's splatfest can be added in, where bladers are split between 2 (or more) teams.
If we're talking about a true 2v2 format, it'll create it own meta as it open up more strategies. There's of course both teams having to worry about friendly fire, but there's ways to avoid or reduce the effects of that. Other strategies I can think of includes, but probably not limited to:
-Spin equalization with a teammate to boost your or their bey spin
-knocking a teammate's bey into a opponent's
-(maybe) knocking a part of a teammate's bey (layer, disc and/or frame, driver, revive armor, dead armor, bullet driver top) into a opponent's bey shortly after the teammate's bey burst, loses it armor, and/or the the bullet top detaches from it.
If we're talking about a true 2v2 format, it'll create it own meta as it open up more strategies. There's of course both teams having to worry about friendly fire, but there's ways to avoid or reduce the effects of that. Other strategies I can think of includes, but probably not limited to:
-Spin equalization with a teammate to boost your or their bey spin
-knocking a teammate's bey into a opponent's
-(maybe) knocking a part of a teammate's bey (layer, disc and/or frame, driver, revive armor, dead armor, bullet driver top) into a opponent's bey shortly after the teammate's bey burst, loses it armor, and/or the the bullet top detaches from it.