Well, having a dangly boltsnap on a reel is just a pain when doing tieoffs. With a double ender, you can get that thing out of the way so its cleaner.
The metal to metal connection thing really refers to hard attachments, like using those little chain link things to secure boltsnaps. Dive Rite's regular handle reels are a prime example of that I'm talking about. If the snap jams, you're done.
A double ender has two points that must jam before it can no longer be removed. Slim chance of that happening on properly maintained gear.
and the solution to not losing reels is to clip it off properly
