I have a collar with tags that I leave on all the time.
I
never put a leash on her collar! When you walk them with a collar and a leash their neck is always being pulled.
With a harness this does not happen and you always have better control with them on a harness.
I also have the same tags on her harness but only use her harness, when I take her for walks or going outside.
I guess I am an overprotective parent better safe than sorry!