The myth is "You need to trigger lock all guns while transporting them" But it is only true for restricted firearms.
Yes, but I do lock my NR for transport so that they also meet the storage reg. That way I can park the car and go into a shop or restaurant, visit a friend, or leave them in the car a few hours before unloading them. It is handy that they meet the storage regs and that let's me be a little more spontaneous without worrying about the gun.
Obviously only applies to NR.