Oh no, say it ain't so!!!
When I installed 45.0 it changed all my folders to "Correspondents" all by itself without asking if I wanted to do it. I have, I bet, over 100 folders. I started to change them back to the way they were but gave up when I saw how monumental the task was.
The information that comes 45.1 says something about the "Correspondents" but from what you imply, it just won't force Correspondents, but it won't correct what was forced by 45.0.
If I had paid for Thunderbird I would demand my money back.
Could somebody please create an add-on that will allow quick changing of columns in folders? I'll pay $10.00 if it works. And I bet a lot of others will also.
Something like a spreadsheet with the left column listing all the folders I have. Then each column of the spreadsheet should list potential Thunderbird columns going across. Then I put a "x" in any column I want to appear in the folder on that row. Even better, instead of an "x", a number indicating where the column is located, left to right, in the Thunderbird folder.
$10.00 from me to the person that creates this add-on.