Unequal layout grids (columns) or colspan-like behavior?

Unequal layout grids (columns) or colspan-like behavior?

I'm heavily utilizing grids to format my page.  However, the majority of my content fits better with a 2/3 and 1/3 2-column template.  No problem, I can override the CSS:

.ui-grid-a .ui-block-a { width: 65% }
.ui-grid-a .ui-block-b { width: 35%; }

Except I'm in trouble when I need to use the 50/50 grid, or even a 3 column grid because JQM appears to mark up the grids dynamically and I now have a table with column1 width: 65%, column2 width: 35%, and column3 width: 33%... which of course wraps the content.

Any plans to support defining unequal widths for grids?

Alternatively can someone point me to a colspan-like feature?  I could just as easily get my content layout looking right by specifying a 3 column grid and use a colspan=2.

Thanks!