Storage/Shipping andItem UOM Setup

There are some items we are not able to set up the same way we normally do:

Typically our Storage/Shipping in P4101 is set up with EA on the UPC level, Cases on SCC(PI=1) and Pallets on level SCC(PI=2).  This yields UCC # as follows:

I have a circumstance where I need the case UCC to start with 20...my first thought was to bump the CA and PL's down a line and leave SCC(PI=1).  In addition, I changed my UOM to look like this:

This does not work because the carton recommendation is looking for that first level.  So my next thought was to add a new UOM to the first level (a value added to the UDC for the sole purpose of adding it to this level - this is not something we measure our product in at all).  This is now what it looks like: