Is there a way of creating an empty list of n rows (or adding empty rows to an existing list)?
I can see how to ListInsert a single item, but there doesn't appear to be a mechanism of adding multiple rows e.g.
while LIST.Length < desired_list_length
ListInsert(LIST, Null, 0)
I need to end up with an empty list of a specified length in order to iterate over it and populate its cells.
you can do it with an if and a counter.
simulates a while-loop
If you want to create a really big list, you could ListAppendAll the ListDuplicate of the empty list (starting with a list of length 1), until you have a list larger than half the intended list. But I agree with J. that a simple while-loop is probably all you need :).
For anyone else wanting to do something similar, I hadn't realized you you could use an IF as described above: by simply wiring it back into the flow to create a loop: