Apparently, there is nothing that forbids you to do it. You might want to let them know that you have two applications going if you do because then they can cancel the extra one when the first one goes through. I know in some cases when people have applied for a PNP nomination and already had an FSW going that the PNP has contacted CIC and told them to treat their old FSW as a PNP but they can also request that it not be done if they want to apply again. Of course the more applications you have, the more fees you pay and if they have started processing both, you can not get any refunds when one goes through and you cancel the other.