I would like to make a suggestion for a good idea however i am not sure how good it is since I am new to Logos 4 and the forums but here it goes...
I recently purchased a lexicon only to find out i all ready had it. i understand this is my fault but since Logos knows what I am license to have why can't a simple check be done before charging my CC. This simple check will protect me and others like me from duplicating books I already own.