It could be the remote, but the battery is not that old and it seems to be functioning normally in my tests since. The Harmony remote was also not in use when I had this issue previously (18months+ago, but with different amp but same DAC and streamer).I am not certain I understand your problem fully but something 'similar' occurred when my Rotel Pre/Proc volume started increasing (NOT 'jumped') to its max by itself.
I had found out later that the Logitech Harmony remote control went bonkers [I think] because of low batteries.
Sounds too simplistic but could a R/C be the culprit of your demonic 'High Volume Incident'?
Sorry to hear you damaged a speaker, that is one of my worries too. I am also sorry you didnt get much of a response on the Roon forums, they have generally been pretty good when I have needed some support or help.I use Roon with my Devialet Expert and had one incident recently where Roon went full volume and I couldn’t override this with the device volume control.
I ran and killed the power, but sadly damaged one speaker driver.
I suspect something went wrong with the handshake between Roon and the end point and it stayed on fixed volume rather than variable. I have safety limits set to prevent this but they did not get applied.
I posted on Roon forum and got no response from tech support. Very poor. Others there have cited examples of volume going to max.
I am now very careful when I start up that no music is playing until I am sure the volume has been set to variable.
It is always a potential risk when using software based volume controls I guess.
Might be worth putting your issue as a ticket over at Roon.
I have put the logs up on Roons website, and waiting on a response! Could the DAC pass on a distorted stream, or react in someway to the filtering/DSP settings?This reads to me like a software bug in the way the filtering/DSP was implemented. It is trivial for that part of the pipeline to create massive overload/clipping. I have never seen it in Roon but it is possible.
I bet this is the problem. I more than once was looking at my iPhone when the volume shot to max. This has only ever happened when using Roon. It's been discussed at length on the Roon support forum. Unfortunately, support has yet to provide a reliable fix.