Effect Switching a la EQD Disaster Transport Sr?

[diablochris6]

I have been reading up on the Earthquaker Devices's Disaster Transport Sr. delay monstrosity and how you can have two delay pedals in series, parallel, or parallel with a bleed of delay 1 into delay 2. That seems really interesting either to recreate a similar effect or as a standalone utility box that you could hook up whatever two effects you wanted. I have only seen one gut shot picture, and I am a bit baffled as to how they achieve this with a 3PDT. I might have figured out a similar method using a 4PDT though.
Not shown are the voltage and ground connections of the pedals or the 3PDT switches on the delays. The thick blue line represents the delays in series, and the orange line shows a parallel path. I figure there would have to be two buffer/splitters, one to split the dry signal, and another to split delay #1's output to allow for the bleed, which I guess could be a passive bleed pot. I figure there should be a phase switch in case things get weird, but should there be any problem with hooking up multiple inputs to the input of delay 2 or the output jack without a mixer circuit? Am I way off track?

[diablochris6]

Bump, with more focused questions.

1. Does the switching look reasonable, or is there a better/simpler way to do it?
2. Slightly related to #1, does anyone know how Earthquaker Devices gets away with this switching using a 3PDT?
3. Should there be any concern for multiple signals leading to delay #2 and to the output?
4. Is a mixer necessarily needed if I would rely on the dry/wet signals of each delay?

The parallel/series/bleed concept opens a lot of neat possibilities. I just need a little nudge. Thanks.