If you double click such doofer preset file with extension “.xrdp”, Renoise will use it as a sample 
Which makes no sense at all. Instead, Renoise should add a roofer device to the current track and load that preset.
Yeah. I made a suggestion while 3.0 was in beta, but noone responded. I think that drag’n’drop should work with doofer presets as well. How is doofer sharing supposed to take off when loading the presets are extremely non-intuitive?
Also it would be very nice, if doofers would have it’s own preset database for the child devices, so a roofer preset could cantain various settings… But that’s a dream for R4 I guess.
And if you could use more than 8 knobs, or smaller variants of knobs, or hide only selected parts of the devices, or even REARRANGE the knobs :)Or minimize child devices to one liners, not three liners.