So just like the wiring diragram I showed. on the power out of the relay, you can tie all 3 lines together. 1 wire to the vr sensing line. 1 wire to A field of the ALT. and 1 wire to the supply side of the ballast.
yes running three wires from the relay output will work fine.
if your only voltage to the ballast will be from the relay, be sure that you tie yr ign1 and ign2 wires together on the relay trigger if that's where you are going to pull yr switched power from.
