I run 2 TIU’s with Wi-Fi and remotes as well as Legacy with remotes and Lionel’s Wi-Fi. While a power supply for each port of the TIU sounds like the way to go. I think it’s overkill in the modern age of can motors and LED lighting in cars. One Lionel 180 brick can power up multiple TIU channels. Depends a lot on what your running as far as a draw. If you run smoke. That will factor in. A yard switcher may draw around 2 amps. Most of my mainline trains draw maybe just a bit more. I run smoke only briefly for guests.
I think just running bricks works fine in a command only layout. No need to spend extra money on handles. I have one power supply on a 22 x 48 space. Not an abundance of trackage. But a good long mainline run. It’s a Big Max put out by Davis Electronics years ago. 2 12 amp supply’s in one unit. Haven’t touched the voltage knobs or buttons in years. It powers 7 channels on my TIU’s. I use PSX breakers on the channels. A few channels share the same breaker.