Changes from v4.4.8 (last release version) as follows.
Fix crash in "mcad" where there were DHCP leases with hardware addresses longer than an actual MAC address.
Includes more packages with debug symbols available to help diagnose crashes from submitted core files.
Fix crash in ubnt-util
Fix crash in "redirector"
Note: GeoIP back end has been removed from previous dev build because of variety of problems, will be re-introduced once those are addressed.
Fix DHCPv6 client problem causing renewal failures in some circumstances.
Dynamic DNS back end updates in preparation for expanding DDNS support in controller
L2TP VPN permitted encryption algorithms tightened to remove weak ciphers. All reasonably modern clients are already using a strong option, so there will be no change in behavior. Some ancient clients may not support any of these options.
UniFi reporting back end additions for IPv6
Several display-related fixes and improvements
Fan control improvement for noise reduction at low fan speeds.