They are ready as soon as you add them.  You might learn more
if you turn factotum debugging on:

1) create a window
2) in it 'echo debug > /mnt/factotum/ctl' then 'cat /dev/kprint'
3) try to pull and then send me the output from factotum.
4) finish with 'echo debug > /mnt/factotum/ctl' to turn debugging off