Hi!
With the fix for headers being offset in 9.2.1, it introduced a bug.
It can be seen in the MultiGrid example, by setting fixedColumnCount to 0, and scrolling all the way to the right. The last header item is rendered above the scrollbar, instead of in the last column.
It is also a bit weird to get the extra cellRenderer call with column 0 and row 1 past the declared size of your table. Not sure what the requirements are to solve the original scroll-offset problem, though.