Linux kernel v3.x. If it were updated to v4.x, that's where it would be mentioned
Software configuration control...
To the best of my knowledge, it is the Volumio organisation that produce the software for the USBridge Sparky processor. Perhaps naively, I would therefore assume that they, not Allo, control the configuration of their software and report accurately what changes take place in their changelog.
For the last two updates, the Volumio changelog states:
(Note the line I have underlined and emboldened).
"2.513 (07-12-2018)
FIXES
Fixed crashing bug in UPNP due to incorrect albumart
Fix potential security issue in NAS mounts
Fix Multiroom Device selector
MYVOLUMIO fix to TIDAL login when special characters are included
MYVOLUMIO fix to TIDAL personal playlists
NEW ADDITIONS
Install To Disk added use of eMMC or SD disks
Add version in the plugin information
Add checkcontentformat = 0 to upmpdcli conf
2.502 (31-10-2018)
MYVOLUMIO
TIDAL and QOBUZ native integration
Auto Sync of Favourites, Webradios and Playlist
Remote connection to Volumio devices
NEW ADDITIONS
Add checkcontentformat = 0 to upmpdcli conf
Anonimyze IP for GA
Add multimedia keys support
pi kernel bump to 4.14.71
FIXES
Better handling of error toasts
Fix handling of uncompliant DLNA server
fix volatile default albumart
Fix stop state if no service is defined
Improve volume responsiveness and add disable volume"
So 4.14.71 is there in black and white and that's all I can go on. Have I missed something?