Sorry, when posting updated drawings, I’ve mixed Option A & B diagrams. You originally observed Option B diagram for option A description and visa versa.
SC terminal is a terminal on a Gen 2 controller. Gen 3 has it labeled as 24 V - terminal.
Commons are lines connected from any available C terminal, in case you commons from two controllers tied together. (C terminal of one controller connected to C terminal of another).
Note that you can get away with just one common wire, if you move the original jumper from terminal 5 to terminal 9 and use original common hookup on terminal 13 (Labeled common controller #2).
Update: Please note to remove original jumper from terminal 14 to terminal 8 with the Option B configuration. I’ve accidentally left it in during my write-up.