Besides pagenumbers, Scribus masterpages can currently only hold static elements. Ivan Monroy Lopez wrote us a very handy python script which puts as many linked or unlinked text boxes on as many pages you want. You can also run the script multiple times…

measurements.py
template.py

The script is split into two files: measurements.py and template.py. Template.py should be run from inside Scribus (In the main menu choose: Script > Execute Script). Put info about boxes (size, amount, page start etc.) into measurements.py.

This is what measurements.py looks like if you would want to end up with a 22 page document with 2 linked columns of equal length on each page:

#the script will start inserting boxes at page
start = 1
#the script will stop inserting boxes at page
end = 22
#the definition of text boxes follows the format:
#[x-position, y-position, width, height]
#x and y positions refer to top-left corner of boxes.
#units are based on the default set for the document.

#text boxes needed in even pages. edit as needed.
even = [[0, 0, 100, 100], [100, 100, 100, 100]]

#text boxes needed in odd pages. edit as needed.
odd = [[0, 100, 100, 100], [100, 0, 100, 100]]
#will the text boxes be linked? (yes or no)
link = 'yes'
#link = 'no'

both measurements.py and template.py should be in the same directory.