So I just figured out what this issue was and honestly it seems like a bug, but I’m not sure whose shoulders it would be resting on (IodeOS or Firefox for Android (Fenix) which Iode Browser forks from). Just in case though, I will tag this.
Bug reports
Thought-provoking stories by Pocket is removed if you set Languages > Regional Preferences > Temperature to Fahrenheit instead of Use default.
Address auto-fill is removed if you add a system language such as Vietnamese. If you remove the language, you have to clear the Iode browser activity (by swiping away in recents) to see address auto-fill as an option again.
@AlphaElwedritsch Even though you didn’t directly solve the issue, I appreciate you racking my brain around. Thank you.