Hi Ashley
I found that the fast trigger (for example, "condition: on function" ) will be got by checking event sheets in order . If all "condition: on function" are spited into event sheets, one event sheet has one "condition: on function" then including them in one main event sheet. There would be "not fast" any more since it would check all event sheets in order.
I though all included events will be put into one sheet, so that it only need to check one time to get trigger condition, to be a "fast trigger".