If no one is actively working to address this snap being able to work in strict mode, then we should reconsider the original request for classic confinement. @pedronis and/or @niemeyer - it wasn’t clear to me that there was a clear call on if this should be made classic in the meantime. Should it?
The new interface work doesn’t seem completely trivial. Is not also clear to me how good/bad would be the timeliness of changing the access based whether the block device is mounted or not?
I don’t think granting classic in the interim would be misleading OTOH if the target is core devices it wouldn’t really help but the op requested classic to start with so I suppose that’s not the case/fully the case.
Classic support for now would be great! Thanks!
FYI, https://snapcraft.io/fwup doesn’t seem to exist (I guess cause the snap is private?)
While I appreciate the discussion in this thread, it isn’t immediately apparent why a firmware updater would need access to all block devices on the system (or classic for that matter), however, we don’t have anything better.
Perhaps the description could be updated to say something about this access? Eg, currently the description in the store says: “Configurable embedded Linux firmware update creator and runner”. Perhaps say something along the lines of: “Configurable embedded Linux firmware update creator and runner. Supports writing firmware to MicroSD cards, foo, bar, …”?
That said, the requirements are understood. @evan, @Wimpress, @popey, @Igor - can one of you perform the vetting?
Sorry, I made fwup private to avoid confusion in case anyone found it. Until the set of responses over the past few days, I had thought things had dropped off everyone’s radar.
Ping snapd advocacy team. 
Granted use of classic. This is now live.
Thanks! I’ll give it a try this weekend and let people know. Thanks for everyone’s help on this.