wait time cannot be less than 1sec?

Yes. It could be less than 1.

AnkuLua already have
continueMultiTouch(table of PSMRL, times [,timeout])

This method is used to simulate multi touch. It will click the objects of the PSMRL table. Each object will be click times times.
If the table objects are PS (Pattern or String), then each of them will be searched for timeout seconds.
If timeout value not given, the default searching time is taken.
continueMultiTouch could not be called by Region.
The timing of continueMultiTouch is also set by setContinueClickTiming.

-- example for calculator plus
png7 = find("7.png")
loc1 = find("1.png"):getTarget()
list = {Pattern("6.png"), png7, "8.png", loc1}
continueMultiTouch(list, 2)
-- the result is 67816781

Read more: ankulua.boards.net/thread/13/advanced-methods#ixzz4IXrg6E5Y