See discussion of accessibility problems in bug 924915 comment #34 and 35. Especially on Linux, it is barely possible to do mouse click emulation, so turning it on and off, and doing other actions must be made available to keyboard users. Best way would be to add functions to the Tools menu of the regular old-style menu system (not the Thunderbird button menu), since that is what especialy blind keyboard users will be using. We need to have info from a Linux user affected by a bad performance bug in Thunderbird accessibility without which we cannot proceed.

Marcoz indicates this si still an issue :( Still needed for things like bug 924915 and some of the others in https://mzl.la/2MPRSz5

We do have keyboard shortcuts to start/end the profiler with the new addon. On Linux this is ctrl-1 to start or stop the profiler, and ctrl-2 to capture. If you use a keyboard where "1" is at the top of the key, you need to add "shift". If you use Mac, it's probably Cmd instead of Ctrl. I'm unsure what the status of Thunderbird is though. Likely it's using the old add-on because it doesn't support WebExtensions yet ?

The add-on in Thunderbird has not worked for a long, long time. Ref bug 1106414

Thanks, I commented in that bug to at least give an update of the current situation. To come back at this issue: the gecko profiling add-on now adds an icon to the button bar at the top of Firefox. Again I don't know what this could mean for Thunderbird... So first I'd like to understand the accessibility of the Gecko Profiler add-on in Firefox (not talking about the analysis interface). How is it nowadays? Is the button in the button bar accessible? Is it possible to change the settings? Thanks