I made a free macOS App Store app that unlocks higher brightness (actually higher nits, not just a color filter). It works by forcing HDR content. I've only tested it on my MacBook Pro 14" M5, but I assume it works on most modern macbooks.
The description says "The best screen poster", but it's meant to say "The best screen booster" (overly aggressive autocorrect in macOS probably).
Youtube link to see how it works here: