Hevy Devy is the original reason I got an Axe FX! The biggest thing with his echo is Parallel Processing. It's basically a way to get a sort of "Wet/Dry/Wet" rig without having to use multiple amp or cab blocks. I use it on every single preset I make!
I put an example of one of my presets below to make it a bit easier to explain.
So, you have the main signal chain going from the guitar, through all your main blocks, to the output. If I were to put my delay and reverb on that same line I would be able to set the mix level and that's all good, normal. But with a W/D/W rig you have two fully wet signals and one fully dry signal so that you can have very prominent delays or reverbs but still have the clarity and definition of a dry signal. You already know that but for future readers looking for solutions I explained anyways.
The way I have this preset set up is I have 2 delays and a Reverb. As you can see, my signal splits after the Rotary block. Actually, it splits 3 times. The reason I do 3 is cause I want 3 different things that don't affect each other, and doesn't interfere with my main signal. Anything in a line affects only what comes after it, so you can get wild with routing! Also, since it's W/D/W, the Delays and Reverbs in the parallel lines have the Mix set to 100% and you control the level of the Delay or Reverb with the Level knob, and set Bypass Mode to MUTE IN, if you don't do these things your signal will be super loud when you bypass the effect as it's basically doubling your signal.
So the first delay (top parallel, right after Rotary) I use as a sort of looper, I use the Hold function to freeze notes so I can solo over top of them. I don't want that loop going into my main delay, so I route it both to the Reverb and the main line (notice it goes back to the main line AFTER the input of my main delay). The reason I do both into the Reverb and to the Main Line is because the Reverb is set to 100% wet and Mute In so the pre-delay on the Reverb would delay the loop making it sound weird and out of time, and if I have the Reverb bypassed it would mute the loop if it wasn't going to the Main Line.
My Main Delay (on bottom parallel) receives my main signal, then sends it to both the Reverb and the Main Line. Again the reason I do both is the same as the other one.
Then my Reverb receives both my main dry signal, as well as the signal coming out of the Loop Delay and my Main Delay. Again, all of them set to 100% wet, set volume/mix with the Level knob.
So as you can see, my dry signal is uninterrupted, but the Delays and Reverbs are still on there. Kind of like Pit Row in NASCAR, they can go down that path and get back on the track without disrupting the main track.
Then just set your delay Config to Stereo, 100% spread width, and use the Ratio knob to set your subdivisions. My favorite is having the Ratio at 66% it gives it a 1/4 over 1/4 triplet feel. You can also just set the Config to Dual and do with with actual subdivisions. On the Dual configuration you can manually pan each delay left or right, and your core tone will always stay in the center unless you change the Balance somewhere.
As far as Devins tone specifically, I really never use Reverb, I use a delay with one longer repeat and one shorter (66% is my go-to), have the level somewhat low but have the Feedback pretty high, it gives it a nice cushion of echo without being too overbearing. I like the Stereo BBD for more rhythmic ambient echo, and I like the 2290 or Vintage Digital or Deluxe Memory Man for more background echo.
If you want, I can build a few block presets and send them to you, just to give you an example to dive into and a starting point.
