Hi,
Maybe, by editing the database table structure. You could try changing the ‘term_reverse’ row in the database from varchar(50) to boolean. That would basically make the field usable, but the information stored would be neglected.
(before making any changes, I highly recommend having a full site + db backup!)
If you have a GUI databse editor like PHPMyAdmin, then it should be easyer. The table you should look for is wp_asp_index. Then you could edit the term_reverse field, and change it to boolean.
I have not tested this, it is just a theory, but there is a slight chance, that it may as well work.