Thanks for the comment about the switches. I just realized I can tap in front of the TIU and get the full 18 volts for the switches all the time and the lights for the layout after the TIU can be adjusted down without diminishing voltage to the switches.
A brick is fairly inexpensive but has no means of adjusting the power. My above system gives me a zero cost way to adjust the power as the channel is empty anyway. I like to power up my layout with the lights glowing and not run trains. When I run them I like the bulbs turned down a few volts.
I should also point out it is a good idea to turn off the signal generator for this channel as there is no point in having it on.