Roundabout way to get Greek letters on macOS keyboard

[kk428]

I want to be able to easily type the occasional Greek letter on my macOS keyboard. The option key sort of does this (option+m gives µ, eg), but it doesn't have nearly enough of the characters I need. My end goal is to be able to do something like option+[letter] to get these Greek letters, but it turns out to be kind of hard to do.

What I have set up now is that when I hit capslock, it switches my U.S. keyboard to Greek. If hit it again, it switches back. This is just an option that's available in System Preferences, I didn't use Karabiner to configure it. Still, it's kind of annoying when typing, so I was wondering if there was a way to change it so that I either:

• Remap left_option (while pressed) to behave like capslock after the key goes up
• Remap left_option+[letter] to the Greek letter of my choice

The issue with the latter I that I don't know how to specify key codes for anything except existing keys on my U.S. keyboard. Which option is more feasible?

Edit: After some messing around I found a way to swap languages within "to", and it almost works, but I'm still missing something:

                            "from": {
                              "key_code": "h",
                              "modifiers": {
                                "mandatory": ["left_option"]
                              }
                            },
                            "to": [
                              {
                                "select_input_source": {
                                    "language": "el"
                                  }
                              },
                              {
                                  "key_code": "h"
                              },
                              {
                                "select_input_source": {
                                    "language": "en"
                                  }
                              }
                            ]

[BrushXue]

It was integrated in Karabiner but disappeared: https://github.com/tekezo/Karabiner/blob/6181ef9c9a6aeecd4162720884fbbaa2596ee03a/src/core/server/Resources/include/checkbox/change_input_source_temporary.xml

[BrushXue]

@tekezo Will you be able to bring this back? Thanks.