Thank you so much for this thread!
Can I ask what you take in consideration for an entry in the Unconfirmed section? Because if there are rumours included, then why not the many reports of songwriters/producers confirming working for her (albeit "recorded" status unknown)?
Some I think are missing/could be included (which section is up to you):
"Today"
"Shine"
"Pleasure You" (Real version - Solo)
"Crazy Girl"
"I'm Aaaaaight"
"Devil In Disguise"
"Follow Me"
"Forgiven"
"Cry"
"Flame Thrower"
"Matches" (Solo version)
The DWAD Tour songs ("Mystic Man", "My Love Was Always There", "Weakness", "You Were My Home")
Maybe the alleged duet with Dionne Warwick?
+
Unknown - Produced by Bloodshy & Avant for 'Britney' (2001)
In a 2023 interview he said they first worked together in 2001 (SOURCE).
Unknown titles - Produced by Fredwreck for 'Blackout' (2007)
He talked about doing three songs with Britney in 2006 (SOURCE). In a 2022 article, he talks again about two songs not making the cut for Blackout (SOURCE), and it's indicated said songs were then recorded by Hilary Duff during Dignity sessions. Although it's not explicitly expressed, it's very tentative to think the two credits he has in Dignity ("Burned" and "Dreamer") were the Blackout scraps.
Unknown - Produced by Fredwreck for 'Femme Fatale' (2011)
He said in Twitter to be working with Britney in Dec 2010 (SOURCE). Later in Feb 2011, he tweeted "Britney time!" (SOURCE) (the tweet date is the next day she recorded Big Fat Bass/met in the studio with will.i.am, so maybe she was doing more stuff).