colspan and rowspan implementation

I'm wondering if it would be possible to implement rowspan and colspan with a little effort. First idea is not to create cells missing a value by default. Then it should be made possible to set cell attributes. For this the rows could get an array with attributes for every cell, which then would be proxied to the cell. Or to handle it similar to rowOptions, but per cell. But what about occlusion rendering? As far as I understand, if a cell with a rowspan attribute would get out of view, then the rest of the cells which are affected by the rowspan, would appear in the wrong column, right? Please share your minds on it, and workarounds or implementation ideas are very appreciated.