Plugins cease to work due change in plugin loading and key shortcuts handling

One example:

Thunderbird cannot anymore handle the "s" key shortcut as expected(handing it over to the Nostalgy++ plugin for doing what it does when receiving this key) and as it worked before the update.

The developer write:

"Attention for TB 78.11:
on TB loading, TB first sets Nostalgy keys, and after that, it sets its own TB keys, overwriting the keysetting of Nostalgy.
In earlier versions of TB, TB did wait with loadiing of addons until TB itself was ready.

That means after TB start, out of the box, the keys do not work.
There is a workaround: open TB addons page (tools-> addons), deactivate Nostalgy++ with the blue slider switch, then reactivate Nostalgy++. Now it sets its key after TB is ready and they stay until the next restart."

IMHO It's not good to introduce such a major functionality and API behaviour change with a minor version update labelled as security.

(A similar thing happened with enigmail, by the way, which has been made impossible to use and replaced with a broken and incomplete internal implementation).

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: thunderbird 1:78.11.0+build1-0ubuntu0.20.10.2
ProcVersionSignature: Ubuntu 5.8.0-59.66-lowlatency 5.8.18
Uname: Linux 5.8.0-59-lowlatency x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu50.7
Architecture: amd64
BuildID: 20210528153351
CasperMD5CheckResult: skip
Channel: Unavailable
CurrentDesktop: ubuntu:GNOME
CurrentDmesg: Error: command ['pkexec', 'dmesg'] failed with exit code 126: Error executing command as another user: Request dismissed
Date: Thu Jul 8 20:47:47 2021
ExecutablePath: /usr/lib/thunderbird/thunderbird
Extensions: extensions.sqlite corrupt or missing
ForcedLayersAccel: False
IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
InstallationDate: Installed on 2020-04-12 (451 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
Locales: extensions.sqlite corrupt or missing
PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/thunderbird/omni.ja:greprefs.js:732
PrefSources: prefs.js
Profiles: Profile0 (Default) - LastVersion=78.11.0/20210528153351 (In use)
RunningIncompatibleAddons: False
SourcePackage: thunderbird
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: Upgraded to groovy on 2020-11-03 (247 days ago)
dmi.bios.date: 02/18/2021
dmi.bios.release: 1.38
dmi.bios.vendor: LENOVO
dmi.bios.version: N2OET51W (1.38 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20QV00CEGE
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T08861 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.23
dmi.modalias: dmi:bvnLENOVO:bvrN2OET51W(1.38):bd02/18/2021:br1.38:efr1.23:svnLENOVO:pn20QV00CEGE:pvrThinkPadX1Extreme2nd:rvnLENOVO:rn20QV00CEGE:rvrSDK0T08861WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad X1 Extreme 2nd
dmi.product.name: 20QV00CEGE
dmi.product.sku: LENOVO_MT_20QV_BU_Think_FM_ThinkPad X1 Extreme 2nd
dmi.product.version: ThinkPad X1 Extreme 2nd
dmi.sys.vendor: LENOVO