We have a module with several factors (line items) we ask our end user to project forward for a year on a monthly basis (i.e. twelve periods).
However quite often they will forecast the same factor for the whole year. We would like the abilitiy for the user therefore to enter in their factors in January and then possibly with a boolean the remaining 11 months to autofill based upon the january figures.
After the user enters in their January override, they should be able to use the "Copy Across" feature. While in the cell, they can click the blue down arrow and in the "Edit" is "Copy Accross". I believe that is what you are looking for.
I would suggest using two line items for each factor, where one would be edited by the end user, and the other would bring his response forward. Booleans are not really good for this, so I would suggest using a list with two items "Yes" and "No".
If you want to see the end result as a boolean - consider creating a third line item that would convert the forwarded response into Boolean with a simple IF formula.
You would need a separate line item, but you can them input into one, and use the value until another entry is made, so if they entered 100 for Jan and then 50 in Aug, it would use 100 for Jan-Jul and then 50 for Aug-Dec
Not great for visualisation, and you need two line items, but functionally it works
Line Item 1 = Input
Line Item 2 = If Input = 0 then Previous (Input) else Input
* Assuming you don't want 0 as the value going forward