Up-to-date changelog:
https://github.com/RMerl/asuswrt-merlin.ng/blob/master/Changelog-NG.txt
Excited to see 384_81918 for mainline + AC86U, been reading a few good things about this build over in Asus Official.
81858 also included "improved connection stability" and "optimized CPU utilization", which are probably included in 81918. Might dirty flash later tonight.
The first 384.18 alpha with 384_81846 on my AC86U has been rock-solid.
EDIT: Pinging
@DarkKnight75 because I know how much you love 81918 and your posts are tempting me to install the latest alpha RMerlin just uploaded

I was on Merlin 384.13 up until a couple of days ago.
EDIT 2: dirty flashed to latest alpha; confirmed DHCP Continuous mode is still enabled.