Sadly not with the 1 M/E 4k. Wonder if it could be opened to do a super source of just 2 pip's with it having a DVE onboard! Be great for 2 camera lives! Don't think its a big request!!;)
For the 2nd pip could you use a pattern / wipe key source and fill it with a camera zoomed wide and cropped. The camera would need to zoom out and reframe for the key.
I don't own an Atem but from the manual this should work.
We have done exactly that Peter and it works fine but scuppers any iso's for any extra post production or Aux feeding! Now were using a Pulse to do the Generic background and first pip pre switcher and that works much better! But why BM can't open the software to do a 2 source super source with the 4k 1 M/E to simplify this obvious want by all who own one!!