I use the SwitchBlade Pro as the center of my pedal board.

Tuner->Looper->SBP In
A Snd->EHX Pog->EHX Enigma Q-Balls->EHX Bass Soul Food->Compressor->EHX Bass Clone->EHX Oceans 11->A Rtn
B Snd -> HX Stomp In // HX Stomp Snd->B Rtn
SBP Out->Amp In

I have all of the A-loop pedals on the top row of the pedalboard. On the bottom row, I have the Stomp, 2 aux foot switches, SBR Pro, Looper, and Tuner.

Most pedals (all of mine except the HX Stomp) have their input on the right and their output on the left. Same for the SBP input and output, BUT loop jacks are on the top and grouped together as A RTN & SND on the left top and B RTN & SND on the right top.

For cable routing, it would be more practical if the output, A RTN and B RTN were on the left side of the unit and the Input, A SND and B SND were on the right side of the unit. So sends would be on the same side of the pedal board as the inputs of most pedals, and the returns would be on the same side of the outputs of most pedals. Extra spacing between the jacks on the side would also help with the 90 degree patch cables.

_____________________________
| Power |
A Rtn | | A Snd
| |
Out | | In
| |
B Rtn | | B Snd
|_____________________________|