This is a limitation of Amazon's API, the way they share their data with us.

You'll notice in the search results that the FBA offers load a split second after everything else. We have to use two APIs, and the FBA offers come from the one that loads after everything else.  

Because FBA offers come from a 2nd API, its complicated to add those to the spreadsheet, technically speaking.

We are working on a way to include this and hope to debut this soon.

Peter