In the desktop book collector (far better than on line), in the export, while Title Sort is a selection, author sort is not. This needs to be a selection. If I export to a spreadsheet, to give a list to a friend, not being able to sort by author is an issue.
Technical answer:
Title Sort is a loose field of a book, so it can be exported per book.
Author is just 1 field, the sortname of an author is a subfield inside an author entry, and is therefore not choosable as an export field.
The good news:
You can still achieve what you’d like to achieve:
Go to Tools > Options.
Click "Sorting/AutoCap/Index
Check the box for “Show Sort Names for Persons”
Now export to text and make sure author is one of your fields, and it will export the sort name of the author, instead of the regular name.
That will do it. However, when you do an export, often to a spreadsheet, it is useful to have both the name and the sort name so you can parse the information better. If you ever do an update to Book Collector (desktop) suggest adding Author Sort to the fields available for export.
Noted.
You could also sync to the CLZ Cloud, and send your friend your share link. Perhaps that would make it easier for your friend to browse and search (and he could sort whatever way he would like to to find books in your collection)
No need to use Connect or anything, because the free CLZ Cloud is included with your Book Collector. Just sync to Cloud, then go to Share your Collectorz.com book collection online » CLZ Cloud for Books and log in. Then use the menu top left to find Cloud Sharing and go from there.