The light kit will include replacement circuit boards that screw into the same place as the current boards and have attached red reflectors so light from one cyclotron will not bleed into the others. It also makes mounting super quick and easy once the pack is opened up.
Yes, that was a big change from the previous electronics boards: support for low voltage battery packs like the one included in the Spirit pack.
f you upgrade to a new sound board that uses a 12V battery pack this light kit board will also work with the 12V battery. The standard spirit sound board that comes with the pack would not, so it would need to be replaced if you decide to use a higher voltage battery pack.