Actually, the building code says tat the tread depth for a single
family dwelling in Nova Scotia is 9". The depth of the tread with the
bullnose is 10", so cut down even without the new laminate nosing, it
will still meet code.
I skipped the preformed treads. I didn't like the extra bumb my brand
had. I also was worried about the very slippery nature of laminate on
my slightly steep basement stairway.
My solution was to use a standard metal stair-nosing. It covers the
original bullnosed stair tread and the front of the laminate tread.
I wouldn't do this on primary/decorative stairways but going into a
nicely finished basement it works well.