After recently incorporating the MTH DCS remote system into my layout, I decided it was time to clean up the wiring too. I mounted the (2) 135-watt Lionel PowerHouses in parallel giving me about 15 amps in to the DCS TIU. I was told the fuses in the TIU can handle that, so hopefully nothing will smoke during a derailment. I'm pretty sure I'll never being pulling near the max load for this layout. I tied the TIU to the Lionel Command Base with their "special" cable, allowing me to run my TMCC locos via the DCS remote.
I also have a Z4000 with one side for mainlines and the other for yard tracks. The PowerHouses feed through the TIU and then to the control panel to one side of a track power toggle switch. The Z4000 outputs feed to the other side of the track power toggles. The center of each switch then goes to the respective track block. These switches are center-off, so i can have my choice of off, fixed 18-volt PowerHouse via TIU/DCS, or variable voltage Z4000 output to any track block.
Some may look at my non color-coded mess and bash it, and I might agree since I guarantee 15 amps going through a terminal strip in the open right near where I need to plug cables in to the TIU would never meet UL Listing standards. But I can only say this: no quirks, no power problems, no stray signals, and DCS quality 10.0 signal everywhere always. Ha! Take that.