Firefox extensions: speed boost + eye protection bundle

Verified 2026-08-10 (machine: Fedora 44, NVIDIA GTX 1660 SUPER, RPM Firefox 153).
Two purposes: speed boost (faster, less CPU/RAM) and eye protection (dark mode).

Installation — ONLY via AMO button (GOTCHA)

The most reliable path is the "Add to Firefox" button on addons.mozilla.org
(user does it themselves, or open the page via xdg-open).

What does NOT work (verified on Fedora 44, Firefox 153):

• Sideload xpi to profile folder (extensions/{id}.xpi) — Firefox ignores it,
  extensions.json not updated. Don't waste time.
• policies.json (/usr/lib64/firefox/distribution/ or /etc/firefox/policies/,
  ExtensionSettings with normal_installed/force_installed) — didn't work.
• firefox --install-extension — flag not in --help (unconfirmed).

Bundle (for speed and eyes)

YourCodecs — video boost (mandatory for NVIDIA without VP9/AV1)

• What: h264ify fork (0.2.0, 2024, MIT), selectively blocks AVC/VP8/VP9/AV1
  on YouTube. Needed when GPU can't handle VP9/AV1 (1660 SUPER: VP9/AV1 not in
  NVDEC — verified with vainfo) — YouTube defaults to VP9, and Firefox
  decodes it on CPU → stuttering on streams.
• Link: https://addons.mozilla.org/en-US/firefox/addon/your-codecs/
• ID: {08146168-5720-4ebb-b6cb-e85b4f9c5d45}
• After install — Ctrl+F5 on YouTube (otherwise old format persists).
• Gotcha: blocking ALL codecs at once = "Your browser cannot play
  video" (by design); for forced AV1 — don't block VP9 and AV1.
• Don't use original h264ify (1.1.0, 2019, unmaintained) — YourCodecs
  is fresher and more flexible.

uBlock Origin — speed boost (ads/trackers)

• What: lightest effective blocker, 10.5M users, recommended,
  1.73.0. Less ads/trackers = less CPU, RAM, traffic — main
  "speed boost" for the browser.
• Link: https://addons.mozilla.org/ru/firefox/addon/ublock-origin/
• ID: user@example.com
• Already installed in user profile (1.73.0) — don't duplicate.