It is good to know someone will use at least one of them, after all.
Truth be told, the add-on set was out of my radar until recently, when I decided to add it to my order, so please excuse me for raising these concerns this late. However, if the PO is not set yet, there is still some room for making fine adjustments to the sets. We all know that any key wider than one unit is more expensive, so if one or two out of the three 2U keys included could be replaced with something of broader appeal, it worth the time discussing.
The OP can always claim that time for changes is over and that the set layout is written in stone. But, asking will not do any harm, while we can get a few nice useful keys.
If the three keys have potential use for any of the GB's buyers the issue can be immediately settled. I just would like to know it. Thank you.