simple soft edge wipe

>>linear wipe won't wipe between two sources<<

If you superimpose it will.

Yes but linear wipe won't wipe between two sources. It's the same idea as crop, which is how I wound up doing it.

All the wipe transitions need edge feathering.

You will find this  effect under Video Effects > Transition > Linear Wipe.

Linear wipe will give you more control over the angle.

But will move it to the Ideas board.

Upvote!  (Except there's no upvote button.)

Need soft edges on the wipe effects.