systemd-udevd delays boot for 4+ minutes when an LVM PV is inside an LV

$ lsb_release -rd
Description: Ubuntu 17.10
Release: 17.10

$ apt-cache policy udev
udev:
  Installed: 234-2ubuntu12.1
  Candidate: 234-2ubuntu12.1
  Version table:
 *** 234-2ubuntu12.1 500
        500 http://us.archive.ubuntu.com/ubuntu artful-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu artful-security/main amd64 Packages
        100 /var/lib/dpkg/status
     234-2ubuntu12 500
        500 http://us.archive.ubuntu.com/ubuntu artful/main amd64 Packages

Expected:

Ubuntu 17.10 booting up as fast as Ubuntu 16.04

What happened instead:

During boot up the system will hang and then a timeout will allow it continue. This happens twice.

The first one occurs right after the network interfaces are renamed. Example:
[ 5.160480] e1000e 0000:02:00.0 enp2s0f0: renamed from eth0
[ 121.345255] raid6: sse2x1 gen() 4431 MB/s

The second one is from /scripts/init-bottom/lvm where 'udevadm --settle' is run.

# we cannot properly synthesize LVM LV change events with udevadm trigger, so
# if we use LVM, we need to let it finish; otherwise we get missing LV symlinks
# (LP #1185394)
if [ -x /sbin/vgchange ]; then
    udevadm settle --timeout=121 || true
fi

Reproducing:

Where $vg is some existing volume group name:

lvcreate -n pvtest -L 20m $vg
pvcreate /dev/$vg/pvtest
reboot

Use case:

KVM/Qemu libvirt VM guest's vda with PV in it stored in host LV.
This is somewhat involuntary as certain appliance VMs come configured this way.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: udev 234-2ubuntu12.1
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.1
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri Nov 10 18:29:33 2017
InstallationDate: Installed on 2017-11-05 (5 days ago)
InstallationMedia: Ubuntu-Server 17.10 "Artful Aardvark" - Release amd64 (20171017.1)
MachineType: System manufacturer System Product Name
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-16-generic root=/dev/mapper/vg1-root ro verbose
SourcePackage: systemd
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/05/2012
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 3029
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: M4A89GTD-PRO/USB3
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3029:bd07/05/2012:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM4A89GTD-PRO/USB3:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.family: To Be Filled By O.E.M.
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer