I don't think there is a clear winner between the Delta and the Bruce. If they are roughly the same size, I agree that easiest handling takes the day.For our first trip south next fall/winter (ICW, Keys, Bahamas) we're purchasing a new gen anchor (no discussion here which one).
My choice is one you didn't offer: sell the Delta and the Bruce and get another new gen anchor, preferably one that breaks down (a Spade, a Raya Tempest, or a Rocna Stowable if you can find one).
Since your secondary is manual you can afford to cut the chain in half and shackle it back together when needed. You might even break it up into three pieces based on weight. Store the pieces in buckets or bags to make carrying them forward easier. Remember the boat may be bouncing around while you are trying to carry things around.
I have a stern anchor complete with roller and windlass. That said I wouldn't stage your Fortress there. I've kedged off lots of times but never from the stern, and used the stern anchor setup exactly once in eight years. That isn't to say you won't store your extra anchors and rode aft in a cockpit locker. Just don't think of it as a stern anchor. Make sure you can deploy from the bow without having to kill yourself in the process.