Subject: displaying lots of checkboxes in one line
Since it’s checkboxes, I suppose you could just define two fields side by side and have six columns in each. Radio buttons would be more complicated.
Otherwise, you might be able to do it by making it a shared field and fiddling with the design using DXL or the C API. The 8-column limit is probably in the UI, and not an inherent limitation, so if you can bypass the UI and work on the design element with code, you can probably get past that.