To do (Steam Machine edition)

Open

Test the Steamify installer pages (after the next build, needs Steamify 2.7.0 with --skip/--boot; the ISO has the branch's bundle until it's released): a "Steam Machine" page (leave out: multi-select, nothing selected = full setup) and a "Start in" page (gaming mode or desktop) after the Desktop page; check /var/log/steamify-install.log for the skipped items and the boot choice. If Calamares doesn't expand ${gs[...]} in shellprocess, the log shows "Unknown item: ${gs[...".
Check the live name after the next build: Hello's subtitle should say "Steamify CachyOS, based on CachyOS rolling" (steamify-customize.sh, run by mkarchiso after the packages; the airootfs copy of os-release is overwritten by a package).
Steamify PR: feat/defaults-mode (2.6.0, b948c20) in steamify-cachyos, pushed, no PR yet (checked 2026-09-27: not on main, newest release v2.5.2). Ready: open it; the user merges (never commit to main). The ISO's first-login step needs 2.6.0 released.
Test on the real Steam Machine from a USB stick (gamescope, LEDs, CEC, power-off) before calling the ISO usable.

Live session (VM, --fremont): Vapor look and layout (Steam Deck wallpaper) at the live login; the power-off module is built for both ISO kernels and loaded at boot, in the VM it returns "No such device" (no AMDI0030 GPIO controller), as designed. Whether it keeps the real Steam Machine off is part of the hardware test.
Regression test 2.6.0 on an existing desktop install (test VM from ssh-ready, --fremont): full first run, re-apply, notifications/CEC/theme off and on again. No errors; user units enabled and running, theme applied and restored live, no first-login autostart with a session.
ISO name: steamify-cachyos-<date>-x86_64.iso (iso_name in archiso/profiledef.sh); the volume label stays COS_<yyyymm>.
VM install from the ISO (2026-09-27, f42859a): a VM install from the ISO (Hello's Install, no manual fixes) ran Steamify's step: every component OK, exit: 0, SDDM autologin into gamescope. First desktop login (session switched to plasma in the VM) passed too: Vapor layout, the app opened with everything on. The first-login script runs the newest release, so it only works once 2.6.0 is released (in the test it was pointed at the bundle). The VM's text console doesn't show (virgl): read the installed disk with qemu-nbd -r + mount -o ro,rescue=nologreplay,subvol=@ (logs in @log).

Checkboxes instead of the leave-out list: Calamares has no ready checkbox page whose ticks come out as plain ids (netinstall's are package installs); it would take a QML page (packagechooserq) or a small C++ module. Steamify's side (--skip, --boot) stays the same.
Branding: the live session's os-release says "Steamify, based on CachyOS" (Hello's subtitle); Hello's window title and the boot menu still say CachyOS. Check with the CachyOS team.
Release: a CI job that builds the ISO (privileged container, flags from the steam-machine-iso skill) and hosts it (>2 GB, not a GitHub release asset).
Drop the Boost 1.91 workaround in steamify-prepare.sh once cachyos-calamares-next is rebuilt against the repos' Boost.

Build and test details: the steam-machine-iso skill in steamify-cachyos-dev.