The Lenovo 500e (Gemini Lake) still had no sound after the re-probe because the initramfs never contained sof-glk.ri: sof-bin ships it as a symlink to sof-apl.ri and the firmware copy used `find -type f`, which skips links. Copy links too (cp -L dereferences them into real files). cfg80211 loads regulatory.db once at kernel init, before the stub can offer the unpacked tree, so the Chromebook path stayed on the world regdomain. The stub now carries regulatory.db itself (~6 KB). The stub's readiness wait used grep and tr, which its busybox does not link, so every wait ran the full 8 s. Use globs and tests instead, and link grep and tr for the log line.