Please remove the word "COLUMN" from the sort keys to streamline choosing columns. Currently we have to scroll through all the columns when hitting a key will jump directly to the selection starting with that key.
This has been implemented for LO 7.4, as a fix for bug 140290.
You can use it straight away in our currently supported versions, 7.4 and 7.5.
*** This bug has been marked as a duplicate of bug 140290 ***