One gram of powder? Wow. I epoxy a thin little steel plate on the forward end of the shearpin hole in the thin walled cardboard tube to assist with "shearing"
and tailor the NC shoulder to allow for it. Two should be enough.
The deal with the NC shearpins is one wants to prevent an apogee deployment of the main recovery laundry of a high flying rocket period. If the apogee charge
is a little "robust" and the recovery package slides easily in the tube, the momentum of the drogue/apogee deployment could cause the main chute to push off the nosecone.
All's you have to do is lose one pricey rocket with a lot of hardware to an unintended apogee main deployment and you'll rethink your strategy.
I heard many a lamentation from fliers who lost rockets in that fashion and I started with shearpins early on when I started out.
Sure, if you have a DD that doesn't go that high, can normally see all the events and you can "tolerate" a main at apogee, by all means friction fit.
If you can tolerate a farther walk to recover, fine. If your DD rocket is going up to "outta sight" land for a bit of time, don't have a tracker and count
on being able to get a visual as it's coming down fast, you could lose it as it starts drifting and you can't get a visual on it if it's main at apogee time. You got a tracker? ok that'll help. If it's a GPS tracker you'd be in a better position especially if following the rocket on a real time map. Then again, could end up to be a long drive. Better to prevent an adverse event than have to resort to a backup and perhaps laborious tracking plan.
Kurt