Just coming out of recovery from a failing Podtronics rectifier/regulator, I went back to the stock rectifier/regulator/RM21 setup. According to my Sparkbright voltage monitor, we're maintaining, at idle, somewhere between 12.25 and 12.45 volts. This is running stock ignition, 20W (on low/dip) LED headlamp, followed by incandescent pilot light, tail light, and instrument gauges. The light turns green (>13.2 V) at anything above 1500 rpm. My longest traffic light is better (worse?) than three minutes, and the voltage doesn't drop below 12.25 volts during that time. It may not necessarily be charging, but it doesn't seem like it's losing, either.
You mention an LED pilot light; can I assume that you do not run the main bulb all the time? My ride won't tolerate sitting at a traffic stop with the headlamp on and the brake held on, or the winkers running steady, but it does float the LED headlamp and (incandescent) pilot. If you aren't able to float the pilot light alone at an idle, I suspect you're having charging issues above and beyond merely needing more power. An issue that was pointed out by Thomas
update-the-battery-charging-system-t23131.html?hilit=stator#p303781 is the possibility of weak magnets on the rotor. There's a procedure in the manual for checking alternator output at the source that would be a good starting point to ensure that part of the system is up to snuff.
You might consider converting everything else over to LED also (like I'll be doing this winter). Jean did a bang-up job with some home-brew lights here
diy-led-lights-cheap-t21177.html Obviously, this won't fix a weak charging system, but it is a bit more tolerant of low power.
Nathan