This can be done using the Manual Page Order in imposition.
Impose the document 1up using the Automatic Press sheet size. The above will make the imposed document the same size as the unimposed document.
Use the following page order to reorder pages
The manual page order defined a pattern for consuming the pages in a document.
In most cases this pattern may fill a sheet but that's not required.
The pattern may be less than the number of rows and columns. In this case the pattern may be repeated within an imposed sheet.
Also, the pattern may be more than the number of rows and columns. In this case (as in the above case) the pattern may span multiple imposed sheets.
In the above example, the first page of the imposed document will have page 2, the second page will have page 1.
The page numbers are then incremented by 2 and additional pages (pages 4 and 3) are imposed).
The imposition is repeated until all document pages are consumed.
Received the following question via email
I have a machine that does not have an option to change face up or down function. Front end is also pointless. I'm curious if there is a way in core to flip flop even and odd pages. I've created the workflow that does reverse order, and imposition that creates correct beltsortting (slit merge is not an option). Basically I need back side to print first. The job has to stay in the sequence.