I won't attempt to answer all of your 'why' questions, but I respect your frustration on coping with a new release. There are many changes. Part of this frustration we share is that we are experiencing a new version, one with much new code (which was part of the goal), so I believe there will be continual refinements. There is no good answer ever for 'Why?, as the response may well be "because it doesn't do that (yet).' On setting all accounts to a predefined setting, that feature has never been available, as this is account-specific. All I can suggest is to work with what is there and anticipate refinements as it goes.

Thanks. I appreciate the response. Nevertheless, despite the phrasing of the "why" questions, they highlight functionality that is so strange that it is essentially unusable (as in not fit for purpose). That means prioritised "refinement" is indicated. In addition, points 4 and 5 may well be for functionality that has never existed, but ,as you say, it's part of refining what is possible, and those two points are refinements that speak to convenience and ease of use, which hopefully makes them good candidates for implementation. Thanks.

I'm having a similar problem with Search Messages windows (opened using Ctrl+Shift+F). Even worse, in these windows I am unable to resize columns to permit viewing the entire date/time column, other than by maximizing the window (which I don't wish to do).

This is still the case after updating to 115.3.2 (32-bit).

In Thunderbird 115.4.2 (64-bit), running under Windows 11 Pro, Version 22H2, Build 22621.2428, I see the same problem as described by David C. -- example views are attached. First is the default view, second is after grabbing any of column handles and dragging left. I also do not want to maximize the window.

this is https://bugzilla.mozilla.org/show_bug.cgi?id=1834656