Duplicate Bill Warning Function - Would Anyone Find This Useful?

Hi, I'm relatively new to Reckon One and am just getting to grips with the system.  I'm just gauging response from an issue I have noticed, Reckon One (UK) does not warn when you are entering in a duplicate bill like other software programs will. 

I find this invaluable due to the amount of duplicate bills that we bookkeepers can receive, maybe due to a bill being sent out, paid late and another being posted with a statement, or a client printing off a couple of copies by accident, etc etc, you know the drill, I've one client who regularly sends me several prints of one bill (one of my 'papers in a binliner' clients).  For the life of me I cannot understand why Reckon One developers find it useful to create a unique
bill number but not allow you to enter the (already unique) number that has
been assigned to the bill by the supplier.  

I can only think it is easier for the design team as it is certainly not any use for the end user.  This has been a deal breaker for me I'm afraid, I'm going to have to hold back on converting my clients because I do heavily rely on this function, I have used it to pick up errors in new jobs and saved clients thousands in some cases where they have unwittingly paid a bill twice and the supplier has kept quiet. Using Reckon One means I will have to enter the bills and then run manual checks for duplicates, not a big job for smaller clients but for those with hundreds of transactions per month it's an extra task open to human error. I'm trying to streamline my systems not create more layers of work. 

When I telephoned the customer service team I was told it had never been brought up as an issue, I mean they weren't even aware it could happen and asked why I would have 2 bills the same.... I find it incredulous that other bookeepers have never experienced duplicate bills before and don't find the warning functions in other software useful. 

Would anyone else find this function useful if it was introduced?  I do like the software and find it a pity they won't be looking at this as it is apparently a non issue. Am I being pedantic or is this not an issue for others?