Not that I expected anything to change considering the patches submitted, but Oct 21 snapshot (minus "Add support to create and convert disk images from existing images") is similarly afflicted. Any candidate fixes or patches for added logging will be put to test in short order :)
ci-openbsd$ dmesg | head OpenBSD 6.4-current (GENERIC.MP) #376: Sun Oct 21 22:46:20 MDT 2018 dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP real mem = 17163079680 (16367MB) avail mem = 16633651200 (15863MB) mpath0 at root scsibus0 at mpath0: 256 targets mainbus0 at root bios0 at mainbus0: SMBIOS rev. 2.4 @ 0xbffffcf0 (20 entries) bios0: vendor Google version "Google" date 01/01/2011 bios0: Google Google Compute Engine ci-openbsd$ ps ax | grep vm 75798 ?? Is 0:00.04 vmd: priv (vmd) 70138 ?? Isp 0:02.35 /usr/sbin/vmd 49408 ?? Isp 0:01.25 vmd: vmm (vmd) 87301 ?? Isp 0:04.63 vmd: control (vmd) 83798 ?? Rp/2 874:45.69 vmd: ci-openbsd-main-0 (vmd) 74819 ?? Rp/0 469:43.70 vmd: ci-openbsd-main-1 (vmd) 52785 ?? Rp/3 8:04.52 vmd: ci-openbsd-main-2 (vmd) 58963 ?? Ip 0:00.02 vmctl stop ci-openbsd-main-0 -f -w 25424 ?? Ip 0:00.02 vmctl stop ci-openbsd-main-1 -f -w 58043 p3 S+p 0:00.01 grep vm