Quoted from TimeBandit:
That's it! Put the second board in and splice some fibre from it and have both boards connected with some sort of optical isolating switch so you can choose which source you want to run with. As long as there is room under the playfield to have both sets of drivers installed.
Youre kidding right? If not this wouldnt work at all. You either connect the fiber tubes to the existing stern light engine or the new eli light engine, not both.