I understand. Anyway, I suggest the following approach. You can connect a HumanUI component to the press-button and it will work the way I think you would expect (notice the Rhino Command Line after pressing the button) :
However, for some reason the GH canvas gets into a non-responsive state every odd number of times the command is activated. Perhaps @DavidRutten can fix this.
(You can try the gh definition attached but be aware of that the non-responsiveness still must be fixed. Repeat the command to unlock the “freeze”).
Here’s the script. Double-click it to see the code inside.
Assign Selection To Component.gh (4.1 KB)
// Rolf