I'm not sure about counting instructional flights as commercial ones but there is a requirement to take all flying (with one or two exceptions) into account for the purposes of FTL. In other words, you cannot do, say, 14 consecutive days of flight duty for the giving of instruction then decide you are going to do a CAT job.
One is either in the FTL scheme or not; one cannot dip in and out of it playing one off against the other.
As far as I am aware, this has always been the case.