I have many (17 total) of the PWD function decoders installed in my LGB passenger wagons. They work perfectly as replacements for the original regulator boards with only one issue. They regulate the output at 5V. I don't know that it is adjustable. The original voltage regulator boards in 4 axle LGB wagons actually put out 7 to 8 volts even though the bulbs are nominally rated at 5V. As a result, the lights are dimmer than stock with the PWD boards. I got around this by replacing the LGB bulbs with 5V bulbs that consume about 100 mA each rather than the original 33 mA LGB bulbs. This restored the brightness plus a bit. The additional current consumption is not an issue for me, in fact, I have some additional PWD decoder boards I have since ordered to convert three additional passenger wagons. This would not be an issue if the incandescent bulbs are replaced with LEDs.
I am also using some MD SWD servo switch decoder/motors. I used them to replace one of the original LGB EPL motors on my dual uncouplers.
Dual LGB 10560 electric uncouplers. It works great. I'm using it's auxiliary output to turn on the uncoupling lantern in the unmodified uncoupler. This eliminated the need for a LGB supplementary switch on the un-modified uncoupler.
By the way, the SWD actuating bar has been redesigned so it now will operate the LGB turnout lanterns which is a great improvement. I use turnout lanterns to visually verify point settings. I will be using these newer models to replace the manual operator on any future LGB R5 turnouts I install. They are much more cost effective than buying separate EPL drives and switch decoders.