Current table template architecture doesn't support inner horizontal or vertical cell borders

From the PowerPoint team while doing their implementation planning review of ODF 1.2 CD06:

We've tried examining various workarounds, including flattening the inner border properties onto the table itself (rather than storing them in the table template), but all of the workarounds so far have very bad consequences. Further, a large percentage of our default table styles have inner border formatting (most like the one highlighted above are formatted to not have any inner borders).

Our "ask" is to propose a specification revision to OASIS to provide better support for formatting options for inner borders within the ODF table template architecture.

Here's an example of the issue we're experiencing:
ODF table-templates use styles with the family table-cell to persist their styles, including border styles.

This is a problem because it doesn't allow to have styles like this:
<pic of table with each row alternating border/no border and color/no color>
Notice how the table has a border around it as well as borders between rows, but no inter-cell borders between columns.

The ODF v1.2 spec has these attributes to store borders:
fo:border
fo:border-left
fo:border-right
fo:border-top
fo:border-bottom
style:diagonal-tl-br
style:diagonal-bl-tr

In order to fully support our table templates, we'd need two more attributes, possible names for these could be:
fo:border-inner-horizontal
fo:border-inner-vertical