1.0.3 — now supports Thunderbird 153

Compatibility widened to 140.0 – 153.* after verifying the add-on on Thunderbird 153.0.1 as well as Betterbird 140.13.0esr. No code changes were needed — every element ID, item-id, class, <key> and tab mode it relies on still exists in 153, and a real run there confirmed the spaces buttons get hidden, the shortcuts get disabled, the Tools menu entry appears and the prefs are applied.

Install: download the .xpi below, then Add-ons and Themes → gear → Install Add-on From File. Thunderbird does not require signed add-ons on any channel. Then open Tools → Space Control….

Heads up on the Release channel: Thunderbird intends to stop honouring Experiment APIs on Release, gated by extensions.experiments.suppressed. It is false in shipped 153.0.1, so this works today; the switch now targets the 2027 ESR. When it flips, this add-on keeps working on ESR, Beta, Daily and Betterbird, but not on Release.

1.0.2 — first working release

Switch off the Address Book, Calendar, Tasks and Chat spaces individually. Mail and Settings always stay.

Install: download the .xpi below, then in Thunderbird/Betterbird go to Add-ons and Themes → gear → Install Add-on From File. No signing is needed — Thunderbird does not require signed add-ons on any channel.

Then open Tools → Space Control… to pick your spaces. Nothing is hidden until you switch something off.

Requires Thunderbird or Betterbird 140 ESR (pinned 140.*; the element IDs it hides were read from that version and need re-verifying before the range is widened).

See CHANGELOG.md for what was broken in 1.0.0/1.0.1.