Hey Trestle,
In the attached pictures I am just starting a moderate sized layout 24 x 14. Before drywall I ran 5 separate runs of 14-3 romex from a location under the layout but near the door to the powered end of 5 separate lighting tracks. By using 14-3 wire and installing JUNO 2 circuit track I was able to control 2 different groups of lighting track heads on each single track. When using two circuit track you move a tab on each track head to choose circuit A or B
That is I now have 10 individual circuits at a common junction box. Today I have them switched all on for construction. When the layout is done, I will connect the different circuits to a scene controller next to the junction box under the layout.
I will then have two remote controls (one mounted at the door) (and one at the train controls). With the ability to use different LEDs, aim individual track heads, add or subtract track heads, Dim and combine circuits; I will create several scenes ie: work lights (all on including 5000K leds full bright) Daylight (all 3500K on bright) dawn /Dusk (a few 2000K on low) Night (a few on dim over controls) etc. You get the idea.
I bought the equipment; bulbs at Depot, Tracks from Juno distributor, Track heads from the auction site, I will buy the Lutron controller from Platt or on auction site.
Anyways no matter what I build or how I want to light a scene lit I should have it covered. If not, you can even extend or "T" off of installed tracks. A little confusing to write let me know by email if I can clarify.
Good luck, kevin