In this case, believe
the master of plugins 
That tweak make it the Default (for future add, and metadata update).
If you want the Author to shoe LN, FN and the Sort to be LN, FN. set the tweak to copy.
If the Author Shows LN, FN but the sort Is (or shows red)Select all the books with this problem: Select Bulk metadata edit mod (the E key with 2+ books selected) and tick the box,
automatically set Author sort
This will update the sort value following the tweek rules set (for those books). It will not affect the Value in the Authors column..
For those: use the Quality check plugin, then follow with the bulk trick above.