Experiments without upper limit in ATN for which can be installed in Thunderbird 149. (28) 2026-04-18

#	Id	Name	Users	TB78	TB91	TB102	TB115	TB128	TB140	TB149	Activity	Current	Min (ATN)	Max (XPI)	Max (ATN)	Notes
5	4654	Remove Duplicate Messages	101975	0.5.2.2	0.5.4b5	0.5.4b5	0.5.4b5	0.6.4	0.6.4	0.6.4	2025-11-07	0.6.4	128.0	144.*	*
50	989207	Close to Tray (for Windows)	11343	1.6	1.6	1.6	1.6	1.6	1.6	1.6	2026-01-31	1.6	76.0	149.*	*
74	987906	Full Address Column	5979	1.0.4	1.0.4	1.0.4	1.2.4	1.2.4	1.2.4	1.2.4	2025-05-16	1.2.4	115.10.0	133.*	*
88	986682	Disable DragAndDrop (New)	4335	5.5.0	5.5.0	5.5.0	5.5.0	6.9.0	6.9.0	6.9.0	2026-01-18	6.9.0	128.0	149.*	*
96	11646	No Message Pane Sort	3962	2.0.2	2.0.2	2.0.2	3.0.2	3.0.2	3.0.2	3.0.2	2023-07-21	3.0.2	115.0	116.*	*
108	987764	Header Tools Improved	3134	3.7	3.9	3.9	4.7	4.12	4.12	4.12	2025-09-27	4.12	128.0	145.*	*
109	986692	Profile Switcher	3127	2.6	2.6	2.6	3.3	3.7	3.7	3.7	2025-06-27	3.7	128.0	141.*	*
112	988190	Old (classic) Icons	3061	1.0.4	1.2.2	1.5.2	1.6	1.7.1	1.7.1	1.7.1	2025-03-09	1.7.1	128.0	138.*	*
121	988195	Filter Manager	2579	1.0	1.1	1.1	1.3	1.3	1.3	1.3	2025-01-26	1.3	115.0	136.*	*
127	987911	Spam Scores	2304	1.3.1	1.4.2	1.4.2	1.6.0	1.6.0	1.6.0	1.6.0	2025-11-11	1.6.0	115.0	144.*	*
146	987784	Config Button	1797	1.7	1.8	1.8	2.2	2.2	2.2	2.2	2025-01-26	2.2	115.0	136.*	*
151	310	BiDi Mail UI	1672	0.13	0.13	0.13	0.14.1	0.16.2	0.16.3	0.16.3	2025-10-26	0.16.3	140.0	144.*	*
162	987787	Restart Button	1470	1.3	1.6	1.6	1.6	1.7	1.7	1.7	2025-01-26	1.7	128.0	136.*	*
165	988770	Auto Profile Picture	1392				2.5.0	2.5.0	2.5.0	2.5.0	2026-02-08	2.5.0	112.0	149.*	*
183	987987	Toggle HTML	1180	1.4	1.7	1.7	1.9	1.9	1.9	1.9	2025-01-26	1.9	115.0	136.*	*
184	360086	Toggle Headers	1179	3.0	3.0	3.0	4.2	4.2	4.2	4.2	2025-04-07	4.2	115.0	139.*	*
216	407832	Filter Button	859			2.0.3	2.0.5	2.0.5	2.0.5	2.0.5	2024-08-08	2.0.5	115.0	128.*	*
217	987786	DevTools Button	858	1.3	1.5	1.5	1.6	1.6	1.6	1.6	2025-01-26	1.6	115.0	136.*	*
237	161710	More Snooze	728	3.3.3	3.3.3	3.3.3	3.3.3	4.0.0	4.0.0	4.0.0	2025-04-09	4.0.0	128.0	137.*	*
267	161820	AlertSwitch	603	0.9.14	0.9.14	0.9.14	1.0	1.0	1.0	1.0	2024-08-23	1.0	115.0	130.*	*
392	988849	Calendar event from email with date de	224					0.17	0.17	0.17	2026-03-29	0.17	128.0	147.*	*
474	986230	Mailing list filter	133	3.0.1		4.0.0	4.0.0	5.1.0	5.1.0	5.1.0	2025-04-09	5.1.0	128.0	137.*	*
477	987868	Next Unread Group (Mark All Read)	130	1.1	1.3	1.3	1.4	1.4	1.4	1.4	2025-01-26	1.4	115.0	136.*	*
478	987869	Next Unread Thread (Mark All Read)	130	1.1	1.3	1.3	1.4	1.4	1.4	1.4	2025-01-26	1.4	115.0	136.*	*
481	987988	Toggle Inline	128	1.2	1.3	1.4	1.5	1.5	1.5	1.5	2025-01-26	1.5	115.0	136.*	*
487	988842	Toggle Dark Reader	124						1.2	1.2	2024-11-14	1.2	133.0	134.*	*
557	987989	Toggle Summary	81	1.3	1.4	1.5	1.6	1.6	1.6	1.6	2025-01-26	1.6	115.0	136.*	*
606	988106	Toggle Address Box	65	1.0	1.0	1.2	1.3	1.3	1.3	1.3	2025-01-26	1.3	115.0	136.*	*

The report is based on work by Christopher Leidigh, extended by John Bieling.