The last lighting board I left in was with a 9 pin silent NCE 'quick plug' installation. Even with them, the factory board is superfluous. On some of the older Athearn's with the so called "high speed" open frame motor, I've used the lighting board that's clipped over the motor as a base to sit the decoder onto with automotive double sided body trim tape, after completely stripping all the electronic bits off. The Econami PNP and TSU2 PNP decoders are generally thinner than the shrink wrapped ones because of the enclosed metal heat sink under the bottom of the decoder. The PNP's do both come with a 2 pin CK socket mounted on the edge of the board, which to me, is a nuisance because of it's height and the fact that the wiring from the plug would hang out over the board's edge. I made inquiries on Soundtraxx's FB page, as to whether it could be safely removed and the current keepers wires directly soldered. I got somewhat grudging agreement. All the other functions above #2 are soldering pads (and very close together), so why not those as well. When you're looking for fractions of space, everything helps. The iPhone 6s plus speakers I am using mostly now, are also very slim, 5mm o'all in a step down shape of 3mm thick each end.