Currently, SelectionControls for EditableText only supports:

• cut
• copy
• paste
• select all

I couldn't find anyway to add the Look Up and Web Search:

• iOS

• Android
  

Use case

The functionality is typical in iOS and android app.

Even if I've my own Text Editing & Selection Controls implementations, I couldn't find a way to programmatically show the iOS look up modal (shown below) or the Android Web search for that matter.

It's worth noting that 'share' is also typical for both iOS & Android, and 'translate' is typical for android phones. 'Look up' is also used on macOS on the right click menu of a selected text.

update 2021-11-14:
iOS 15.0 has a couple of new options:

• translate.
• scan text (typically appears on an empty selection where a user can scan a text).
• replace (not sure if this is new or it's been there before).