Either the FFG Endura or a Stretch would be great choices. I prefer the Stretch personally, but both are excellent. If you were really dedicated to the midlock, you could always try to find an original Manix, which featured the midlock instead of the ball lock.
The Manix 2 Lightweight didn't do it for me the one time I tried it. I'd use it while ultralight backpacking maybe, but for an EDC I want liners. Otherwise it's a bit too light, and doesn't inspire as much confidence as the Endura or even a Delica. I also felt the choil was a bit off, not really what I expected compared to the choil on the Stretch.
BD1 is supposed to be Carpenter's version of Gin-1/G-2, which was the original steel in the first generation of Delicas/Enduras in the 90s. It's known as a good working steel, and I haven't tried it, but I think I'd take VG-10 or 154CM or S30V or ZDP-189 (trying to list what's available for Enduras and Manixes, lol) over it if at all possible.
If you do decide to go Endura, there's a sprint run coming out in Aogami Super Blue steel, which would be a really nice way to get "back in the game." ;-)
C90GRE Stretch 2 ZDP-189 British Racing Green
C28GRE2 Dragonfly 2 ZDP-189 British Racing Green
C12BK2W Matriarch 2 VG-10 Emerson Open
C81G2 Para Military 2 S30V
C81GPRGR2 Para Military 2 K390 Ranger Green
C223GPRGR Para 3 K390 Ranger Green
C90FPIV2 Stretch 2 Straight Spine, VG-10 Rit Dye'd Dark Apple Green