On my layout I have many isolated power blocks each Zone fed by a rotary switch that switches between the two outputs of my Z-4000 transformer and two TMCC power houses to run conventional locos with the Powerhouses. I later added TMCC to all the tracks with coupling capacitors to run in TMCC locos anywhere powered by the Z-4000. Also siding power is switched on and off by the turnout control switches.
This allows me to setup the blocks to run trains in conventional and TMCC at the same time.
Carl Tuveson
http://tuveson.com