Play or wait?

When I get lots of slingos and double slingos twittering away, should I wait until they have all finished or is it better to play other columns and get more slingos or other "play" bits and hope that they will all multiply?

As far as I can see, it makes no difference whether you wait or carry on, the slingos do not appear to affect later power ups if you carry on whilst they are still clocking up. If anyone knows any different, please let us all know.