Just because it’s raining, snowing and there’s all kinds of nastiness outside, I took a Pi, did a fresh ua-netinst install of Raspbian Jessie, upgraded to Stretch and installed the networkaudiod.service.
The good news: I can plug, unplug, turn off and turn on my nano ad nauseam – and upon replugging of turning on HQP Player immediately recognises the lost son. My be worth trying with your Devialet. Note: I had to add the same ‘After=’ line to the service as described in the Cubox NAA thread.
The bad news: as @andybob already noted in the Pi NAA thread, the Pi is a lousy NAA when used with USB. Any seriously upsampled format is pretty much unlistenable (PCM 384 / DSD 128 > light (but plenty) pops; DSD 256 > heavy distortion). Lower rates appear to be fine.
One thing I noticed: when music is stopped from Roon, HQP (as @jussi_laako said) takes a few seconds to release (the play/pause buttons in HQP are pressed in this state, and become unpressed after a few secs).
If I wait out this period, I can safely turn off the nano (in HQP’s networkaudioadapter pulldown, the onboard audio of the Pi will remain visible as NAA, and the nano returns to the menu when switched on again). When I don’t wait and turn off the nano immediately, things go haywire (all Pi-related audio, both onboard and USB disappears and is visible again only after a reboot of the Pi (or a service reload, most probably).
Anyway – that’s what I have. It seems the Pi could fix your connection issues (most likely), but with DSD you really want a Cubox. Or a BeagleBone. Or anything.