It would be dependant on the size and flexibility of the site concerned. Somewhere such as Wembley is large and has numerous differing moves. Somewhere such as Baker Street, although busy, has very few different moves.
Now if we're talking "frames" rather than individual sites, I think we could set a pretty decent record. On our "frame" the pre-selected moves could number in the 100s ;D
Never a good idea to preselect too much, as a former colleague of mine once found out at Aldgate (when it was at Farringdon.) He preselected nearly everything, and promptly dissappeared for a quick toilet break. Only to return to find that after the first train, the site had locked itself up completely and required an AET to cancel down the remaining selections (as the panel was having none of it.) Quite a hefty delay.