I wanted to disable the prompt and button for new Outlook. I found this guide and wrote a few lines of PowerShell to automate it and wanted to share.

# Source https://edi.wang/post/2025/1/20/how-to-stop-automatically-switching-to-new-outlook
$path='HKCU:\Software\Microsoft\Office\16.0\Outlook'

# Remove and create to ensure correct data type
Remove-ItemProperty -Path "$path\Options\General" -Name 'NewOutlookAutoMigrationStage' -ErrorAction SilentlyContinue
New-ItemProperty -Path "$path\Options\General" -Name 'NewOutlookAutoMigrationStage' -Type DWord -Value 1
Remove-ItemProperty -Path "$path\Options\General" -Name 'NewOutlookAutoMigrationStage'
Remove-ItemProperty -Path "$path\Options\General" -Name 'NewOutlookAutoMigrationType'
Remove-Item -Path "$path\NewOutlook"
# Remove and create to ensure correct data type
Remove-ItemProperty -Path "$path\Preferences" -Name 'UseNewOutlook' -ErrorAction SilentlyContinue
New-ItemProperty -Path "$path\Preferences" -Name 'UseNewOutlook' -Type DWord -Value 0
Remove-ItemProperty -Path "$path\Preferences" -Name 'NewOutlookRenudgeStartDate'
Remove-ItemProperty -Path "$path\Preferences" -Name 'NewOutlookRenudgeStartDate'

I just installed Radicale and could not at first figure out how to add a calendar that I could edit in the app. And since I could not find any decent post on the topic, here is how to do it (as of iOS 18.7.3 on an iPhone 13 pro, but I imagine the process being very similar on other devices):

1. Open the Settings application.
2. Scroll to the bottom and open the Apps options.
3. Open settings for the Calendar application.
4. Open Calendar accounts.
5. Add a new account.
6. Chose "other".
7. Chose "CalDav-account".
8. Enter URL and credentials for your Radicale server.

I have SSL set up with Let's Encrypt managed with Caddy so that was all I had to do. I say this because I read one discussion about SSL being needed.