bike wrench

[I'm not allowed to post images because my account is too new, so those imgur links will have to do...]

While dragging my bike through some bushes, the exposed section of its rear brake cable running along the top tube got snagged in a branch and I ended up losing the small plastic piece that goes over the housing to turn the frame's cable guide (?) into a cable housing stop. I believe it's called a stepped ferrule or stepped housing end. Naturally, there is another such piece on the other end of the exposed cable, which I'm pretty sure is identical to the one I lost, so I can show you what it looked like:

https://imgur.com/a/ipdAwKB

My first question: What exactly is this called and where can I buy a replacement? Searching for "brake cable stepped ferrule", "brake cable stepped housing end", "brake cable stop" etc., I can find bits that look similar, but none that are an exact match.

My second question: Considering some bushes were enough to somehow dislodge or break one of these, I'm wondering how safe they are compared to alternatives like e.g. a fully housed brake cable or a different kind of ferrule (maybe made of metal):

That thin plastic step (see highlight in last pic of the album) has to withstand a lot of force and if it breaks the housing will just slide through the guide and the brake will fail.

The cable sliding out might also be a concern: I can see that rotating the ferrule gap to be opposite of the guide gap makes that unlikely and that even if they are aligned it's still unlikely due to the cable's tension opposing it, but I wonder if that's how I lost the other one.

Thanks in advance for any advice!