Was trying to install decoders (EM-13 & FL12) into a new train Nik got for Christmas (been waiting on decoders), and ran into problems with the cab cars. It's a Kato ET425. Unlike the EMUs, the motor car is in one of the cab cars, which makes for getting direction and correct lighting a bit more important.
1) It doesn't look like the FL-12s can be programmed on the main, although the EM-13 can
2) There doesn't seem to be a direction bit in the FL-12. At least I couldn't seem to find it in the spotty documentation and changing it through the "config" option on the NCE DCC system didn't seem to do anything.
Of course since you can't read anything from the FL-12, it's hard to find out if anything happened when you (think you) programmed it.

We'll run it tonight when Niko gets back from ski racing practice. But in a quick test, it looks to be a decent runner.