Apps need permission to modify your lock settings if they do not use a rooted bypass. This permission is usually given through Device Administrators. If you do not see Tasker listed in this section with a permission request, it will not be able to change lock screen settings other than the Swipe. It's the same behavior with tracking apps that can remotely lock your phone.
Samsung Galaxy S® 4 MJA Rooted with CF Auto-Root Tutorial
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If it ain't broke, use a sledge hammer.