No - I change my mind on this again, there was 1 boot freeze yesterday at initrd loading cursor, and 1 again today, but earlier today I copied out the contents of /boot and reformatted that partion as btrfs, copied stuff back, reinstalled the same kernel version, update-grub, then grub-install (from artools-chroot because it wouldn't boot without grub-install I then found). So you would think that kernel image ought to be OK. Intermittent problems like this make it difficult to determine what is going on. Why would it fail at those same points at boot even when the data is rewritten on the drive, presumably it will not occupy the exact same space? But why would it work some times but not others?
$ inxi -v7 -z
Resuming in non X mode: glxinfo not found. For package install advice run: inxi --recommends
System: Host: ax Kernel: 4.18.3-arch1-1-ARTIX x86_64 bits: 64 gcc: 8.2.0
Desktop: Xfce 4.12.4 (Gtk 2.24.32) info: xfce4-panel dm: N/A Distro: Artix Linux
Machine: Device: portable System: Dell product: Precision M4400 serial: N/A Chassis: type: 8 serial: N/A
Mobo: Dell model: 0NY980 serial: N/A BIOS: Dell v: A29 date: 06/04/2013
Battery BAT0: charge: 71.1 Wh 100.0% condition: 71.1/73.3 Wh (97%) volts: 12.0/11.1
model: Sanyo DELL U726H8A Li-ion serial: <filter>status: Full cycles: 0
CPU: Dual core Intel Core2 Duo T9900 (-MCP-) arch: Penryn rev.10 cache: 6144 KB
flags: (lm nx sse sse2 sse3 sse4_1 ssse3 vmx) bmips: 12240
clock speeds: min/max: 800/3068 MHz 1: 1610 MHz 2: 1699 MHz
Memory: Using dmidecode: dmidecode is not installed.
Graphics: Card: NVIDIA G96GLM [Quadro FX 770M] bus-ID: 01:00.0 chip-ID: 10de:065c
Display Server: N/A drivers: nouveau (unloaded: modesetting,fbdev,vesa) tty size: 178x43
Audio: Card Intel 82801I (ICH9 Family) HD Audio Controller
driver: snd_hda_intel bus-ID: 00:1b.0 chip-ID: 8086:293e
Sound: Advanced Linux Sound Architecture v: k4.18.3-arch1-1-ARTIX
Network: Card-1: Intel 82567LM Gigabit Network Connection
driver: e1000e v: 3.2.6-k port: efe0 bus-ID: 00:19.0 chip-ID: 8086:10f5
IF: enp0s25 state: down mac: <filter>
Card-2: Intel Ultimate N WiFi Link 5300 driver: iwlwifi bus-ID: 0c:00.0 chip-ID: 8086:4235
IF: wlp12s0 state: up mac: <filter>
WAN IP: <filter>
IF: wlp12s0 ip-v4: <filter> ip-v6-link: <filter>
IF: enp0s25 ip-v4: N/A ip-v6-link: N/A
Drives: HDD Total Size: 120.0GB (33.0% used)
ID-1: /dev/sda model: SSD2S120SF1200SA size: 120.0GB serial: <filter>
Optical-1: /dev/sr0 model: MATSHITA DVD+-RW UJ862A rev: 1.02 dev-links: cdrom
Features: speed: 24x multisession: yes
audio: yes dvd: yes rw: cd-r,cd-rw,dvd-r,dvd-ram state: running
Partition: ID-1: / size: 30G used: 22G (74%) fs: btrfs dev: /dev/sda4
label: root1 uuid: 7002a85b-74aa-4374-b55a-61067abb4e94
ID-2: /boot size: 1.0G used: 62M (7%) fs: btrfs dev: /dev/sda2
label: N/A uuid: 75c0faca-5886-4abb-aa12-ee239202ffa4
ID-3: swap-1 size: 17.18GB used: 0.00GB (0%) fs: swap dev: /dev/sda3
label: swap uuid: 402f9ace-25f8-4dc7-a7ab-c1ce4cbd34a8
RAID: No RAID data: /proc/mdstat missing-is md_mod kernel module loaded?
Unmounted: ID-1: /dev/sda1 size: 0.00G label: N/A uuid: N/A
ID-2: /dev/sda5 size: 32.21G fs: BTRFS label: 50gb-space uuid: fd15ba9c-c421-4215-bfdb-eef8a7b565ae
ID-3: /dev/sda6 size: 21.47G label: N/A uuid: N/A
Sensors: System Temperatures: cpu: 38.0C mobo: N/A gpu: 56.0
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 184 Uptime: 14 min Memory: 477.6/7968.1MB
Init: N/A v: N/A rc: OpenRC v: 0.38.2 runlevel: default Gcc sys: 8.2.0 alt: 5
Client: Shell (bash 4.4.231 running in xfce4-terminal) inxi: 2.3.56
So I have just downgraded to linux-4.17.14.artix1-1-x86_64.pkg.tar.xz - see what happens now I guess.