Neither, the headlight problem is just the design of the R2LC headlight circuit. The triac needs a load to fire, and the input circuit on the S-C (or an LED headlight) isn't enough to give reliable operation. That's what the load resistor or capacitor is for. The circuit on the R2LC was designed with incandescent bulbs in mind, so this topic never came up until LED lighting starting being used. My input circuit mimics an LED headlight, and so suffered the same issue. Since it wasn't that hard to fix it, I added the fix. FWIW, the ERR TMCC products have the same fix for LED lighting, but the Cruise Commander Lite currently does not. With the new S-C version, this ceases to be a consideration, the headlight should always work if connected.
There is one caveat with the headlight operation with older locomotives which showed up recently. The old LCRU, LCRU2, and any R2LC version prior to C08 have a reversed light output polarity. This is a problem for the Super-Chuffer, and the headlight doesn't function properly. The fix would be to change the input circuit to accept either polarity, but that's a more significant change than adding the cap, so that didn't happen this time. The work-around is to connect the headlight input directly to the track voltage. This enables the headlight output, and the Rule-17 lighting functions. The only thing you lose is the ability to control the headlight from the remote.
