That's a handy trick,For cable ends to prevent unravel here’s my cheepskate poormans version for this….a piece of wire insulation held on with a dot of super glue.
But I need to pull on the end of the cable in order to release it from the brake arm, a crimped on metal end cap is something to grab onto while I push the brake arm forward to release the cable hold from the arm. Without that little crimped on metal cap I would have to use pliers
A glued on piece of wire insulation is just gonna pull off and not work for me, But it's a good DIY trick