Just a note from a guy who took a 28 block DC layout to a 48 block DCC? layout by isolating the turnouts.? For single turnouts, place a signal at least 40 scale feet from the points end of the turnout.? For the frog end of the turnout the turnout number and turnout configuration matters a lot.? For example a No 6 double crossover with 2 inch separation is 40-50 ft from the frog. A number 9 measured about 80 scale feet and a Peco double curved turnout measured about 72 scale feet.? This means that unless you scratch build each turnout there is a little length of rail on each end of the turnout. So don't cut the rail until the track is in place.? Since track configuration matters my advice is to use 2 NMRA track gages and slide them along the frog rails until they touch.? That's the nearest point to cut the rail.??
Another note on resistor wheelsets.? Unless the wheelset somehow can conflict with part of the underside of the car, place it on the outside of the truck.? This is important for backing movements.? Also a thought on detection.? Each time a resistor wheelset enters the block, the resistive value detected halves.??
And a note on the actual signals? My 48 block layout was going to require 92 signal heads.? But looking at the layout on the computer I was able to determine which signals were not really necessary to place on the layout.? They are still part of the signaling system, just not on the layout.
Love PECO turnouts.? Used them for 30 years and had very few failures.
