Creating reminders using KM?

Is there a way to send text, including multi-line notes, to create a reminder in Apple Reminders?

I'm not aware of a native Keyboard Maestro way to do this, but you probably use reminders-cli with Keyboard Maestro to achieve that:

Thanks! Looks promising.

See this GitHub file for examples:
Demonstration of using AppleScript with Reminders.app

You can use AppleScript with KM using a Execute an AppleScript action.

I think IFTTT is made for stuff just like this. It integrates with both SMS and iOS Reminders, which would sync with macOS Reminders via iCloud. If you use an Android phone, the SMS trigger can still be used to execute a macro in Keyboard Maestro in a number of different ways, entirely dependent on personal preference. One example would be:

IFTTT: SMS → New Dropbox File
KM: Folder trigger (Dropbox folder) → AppleScript: New reminder

EDIT: It just occurred to me I may have misinterpreted your phrase "send text" to mean send SMS. Apologies if this is the case.

Thank you!

This is a very nice applescript to create a reminder from the clipboard. https://talk.automators.fm/t/keyboard-shortcut-to-create-new-reminder/2145