[Ridgway81432]

Welcome from Colorado.
I would flush the case and see how much comes out, close to the amount to fill the hole.
What if the hole is from larger pieces that can't drop through the drain plug hole?

 

[Ridgway81432]

Remember the transmission has engine oil in it too.

 

[Ridgway81432]

It is sealed between the 2 cases correct? What exactly are you trying to say will happen?

Two case halves yes, the front part is the crank area with the back part the transmission. The oil moves between them so metal can be in the trans area too.
With the piston that way the engine probably didn't run long for metal to get moved to the trans area, yet I would do my best to flush that area too.