I have a stash of opto isolators already.
But I was also trying to create little projects that others could follow and build. Suggesting that they cut a pin and solder a jumper to it removes the value of suggesting people use the BoB9118. Separating the cathodes seems like a good choice if they revise or update the board. Make the channels independent.
Note - no reference to any site… just suggested for SFE when revising or introducing optical isolation breakout boards.