Variable Intercell Spacing

Is there a clean way to support variable intercell spacing? For all of the column spacing in a spreadsheet are the same value of 10, except between columns 3 and 4 where the desired column spacing is 4. The design rationale is that the content in columns 3 and 4 are very closely related and should physically be closer together on screen.

I realize I could make a cell that combines the contents of these columns for each row, but I wanted to make sure that I wasn't missing something before I go down this path. For example, a datasource callback that query the intercell spacing between columns would be ideal, but I don't see it in the current API.

If this functionality doesn't currently exist, please consider this a friendly feature request. Thanks for the continued efforts on SpreadsheetView. It has been incredibly handy!