Auto-fill search field with selected text

Quite often I like to execute a search for a string that I find in a document or on a web page. At the moment, I have to select the string, copy it, activate Flow Launcher, and then paste it into the search field.

I would prefer if I could just select the string and activate Flow Launcher by a special hotkey so that the search field is automatically pre-filled with the string.

My suggestion is related to #1110. However, the approach suggested there is not optimal, as one would still have to copy the string manually, activate Flow Launcher and then wait for a certain time before the string is automatically pasted into the search field. This is why I suggest a special mode of activating Flow Launcher that automates entering the selected text into the search field, with a special hotkey assigned to this mode.