This is not possible. You can add annotations to the microflow and connect them to the action where they are applicable.
Alternatively you can add explicit splits in the microflow instead of using if/else statements to make the logic easier to read.
Sure, there is a annotation that you can put where you want it to be.
You can add an annotation and connect it to the action you want.
If you have an good idea for a different method, you should post it to the idea forum.