Mine does. I have two oval circuits with several terminal branches. The power feeds from the track have crocodile clips at the end so that when (or more accurately if) I want to use analogue dc I connect the crocodile clips to the terminals on the analogue dc controller. When I go back to DCC I connect the two negative clips together and the two positive clips together and connect them to the DCC power feed. Takes seconds.
I also have the option to have one section analogue and DCC should I wish as the two circuits are isolated due to their analogue origins.
My accessories at this point still comes from the AC output from the analogue controller but when I get my new DCC system and more dosh I will ultimately have them operated from the new system.
What are the constraints when contemplating a dual purpose layout?
Where control of your accessories lies and if you have isolate sections and electrofrog points
Is it better to opt for totally isolated separate layouts within a layout?
Defeats the purpose of having DCC. One of the big selling features of DCC is that you don't have to mess around with all the extensive wiring of isolated sections.