I used for my Anet A8, prusa i3 clone, with a bowden set up. I made some modification to the X carriage to make this fit.
For the volcano your edit works very well.
When i tried to use your design with the normal e3d the schells were up against the center piece bolt holder and could not get high enough.
I used these when I printed them with PLA.
But people should print it with ABS. Because the cable of the hotend is warm enough to soften up the ducts and make them droop onto your prints and scrapped quite some prints of mine.
Eventhough what I will say now is not your fault but the first designer and I'll comment it there as well:
-It's annoying to screw in the ducts onto the center piece. A nuttrap design would have been better.
Instead of a tie-rip hole at the back, a more snug hole for the e3d heatsink would have been better. Could be that my heatsink is off size.
-Somehow the pieces of the duct where the bolts go into, the pieces that touch the center piece, were too wide and clashed and there was too little room for a good bolt hole. (could have been my printer but I did quite some flow tests before hand, so i doubt that was the case.)
-If too much pressure is applied the bolt holders break way too easily. There is enough room to make these wider.
-Eventhough there is enough room for a newer e3d aluminum hotend blok with an cylindrical thermister to spin around, there is too little room for the cables, which also heat up. Thus the heat of the hotend simply heat up the ducts and make the soft and potentially droop.
-Due to me screwing around with a broken bolt holder, it started to resonate terribly.
In conclusion I cannot recommend this for Anet A8 or prusa i3 clone users. But apparently a lot of people like it so it's good if it's printed in ABS or better filaments with a better calibrated printer, but the other issues still stand.