There is some documentation here: http://kb.mozillazine.org/Mail_and_news_settings

I'm not aware of any 'official' list. Web searches are your best bet, e.g.:

https://superuser.com/questions/13518/change-the-default-sorting-order-in-thunderbird

There is some documentation here: http://kb.mozillazine.org/Mail_and_news_settings I'm not aware of any 'official' list. Web searches are your best bet, e.g.: https://superuser.com/questions/13518/change-the-default-sorting-order-in-thunderbird

Thanks for the reply, sfhowes! I really do appreciate it.

I had already found that first link you supplied, but it doesn't have any info on the meaning of the individual values for the two preferences I mentioned.

The second link makes me a bit suspicious since that answer is from 14 years ago, especially since the official config editor docs at https://support.mozilla.org/en-US/kb/config-editor say "Setting values to something other than default values is not supported, because Thunderbird developers may change or deprecate the preference in the future."

I'll probably take your advice and just keep on googling, though v115 has wasted so much of my time that I'm about to just switch to f*%$ing Outlook.  :-(

This may help:

sort_type:
  byNone        17         byPriority    23      byLocation    29 
  byDate        18 *       byStatus      24       byTags        30 
  bySubject     19 *       bySize        25       byJunkStatus  31 
  byAuthor      20 *       byFlagged     26      byAttachments 32 
  byId          21 **      byUnread      27      byAccount     33 
  byThread      22         byRecipient   28      byCustom      34 
    * = commonly desired values
   ** = by Order Received (?)

sort_order:
  ascending   1
  descending  2
  
  mailnews.default_sort_type     18 (date)
  mailnews.default_sort_order    1-ascending, 2=descending 
  mailnews.default_view_flags    0=unthreaded, 1=threaded
  

This may help:

sort_type:
  byNone        17         byPriority    23      byLocation    29 
  byDate        18 *       byStatus      24       byTags        30 
  bySubject     19 *       bySize        25       byJunkStatus  31 
  byAuthor      20 *       byFlagged     26      byAttachments 32 
  byId          21 **      byUnread      27      byAccount     33 
  byThread      22         byRecipient   28      byCustom      34 
    * = commonly desired values
   ** = by Order Received (?)

sort_order:
  ascending   1
  descending  2
  
  mailnews.default_sort_type     18 (date)
  mailnews.default_sort_order    1-ascending, 2=descending 
  mailnews.default_view_flags    0=unthreaded, 1=threaded
  

Thanks, david! Where is all that from?

As @sfhowes alluded, I found it in various help web pages. Here is an example: https://superuser.com/questions/13518/change-the-default-sorting-order-in-thunderbird

Thank you, david! I'm hoping that setting the mailnews.default_view_flags to 0 does what I need. <fingers crossed> I appreciate your responses.

Yes, I've provided extensive documentation on unthreading to many with success, so I'm confident it works. Remember, that changes the default, but it doesn't change any folder settings.

Just a follow up to close the loop for others who may read this. I was able to finally stop the constant automatic resetting of the sort on my inbox to threaded by setting mailnews.default_view_flags to 0 via the config editor. Thunderbird is usable once again.