Not all of these changes will impact your use of DBMC, but in case you're interested, 16.3.0 to 16.6.0 saw these changes:
FIX: crash on exit
FIX: WOL
FIX: Hiccups in plain Mediacodec
FIX: Regressions
ADD: SD hw setting for HEVC
FIX: Crash in new Network code
FIX: Crash on AML 6.01 FW
ADD: Limit AC3 encoder to 384kbs with Quality & High
CHG: API 21+ (Android 5.0) only, sorry.
ADD: DASH support (aka 1080p4K youtube)
ADD: Builtin log (Settings-System-Logging-Upload…)
ADD: crash handler (no need for logcat)
FIX: Only stop Surface when really necessary
CHG: Revert to Surface as standard
ADD: acceleration setting for hevc
REVERT: crash when enumerating sound devices during a refresh rate change
FIX: Missing start of video with large buffer
FIX: stalls after seek
FIX: [includeall] avoid double episodes
CHG: Enable YADIF for arm
ADD: Export single item to NFO via context menu
FIX: Properly cache if both audio and video are starving
FIX: GLES font corruption inevitable after few days runtime