Borderlands 4 split-screen performance isn't the greatest, but there is a way to make it more tolerable. Borderlands 3 split-screen co-op was riddled with issues, and so I went into Borderlands 4 ...
The upcoming Android 16 update may let you put two apps into a 90:10 ratio in split-screen mode. This means one app will take up 90% of the screen while the other app takes up the remaining 10%.