> [However, I have my own extension to the column-sorting that adds a
> Time column, which shows the `buffer-display-time'. If I sort on
> that column, will I need to re-sort? I don't know - is
> `buffer-display-time' what is used in your ordering? That's what my
> "Time" column uses.]

No, Emacs simply uses the above mentioned frame parameter together
with the global list to generate the frame-local ordering---it doesn't
mess with the recorded display time for this.

Therefore, I think that using the frame-local buffer-list should not
affect your sorting results.

-- 
Károly