KLA-OT2base
small Arch Linux openbox based distro using overlayfs frugal install
The heart of KLA-OT2base (openbox/tint2 Arch Linux based) is a 'FirstRib' magic initrd which uses overlay filesystem to provide frugal install save persistence, typical load squashfs capabilities (including currently unique ability to load uncompressed physical directories into the layers hierarchy), and copy2ram option. Similarly small sized flexible distros are available such as KLA-XFCEbase (also Arch-based), KLU-jam (Ubuntu-based) and KLV-Airedale (Void Linux based).
Lots of configuration information at https://tinylinux.info
Currently discussed/details here: https://forum.puppylinux.com/viewtopic.php?p=71970#p71970