Okay, the Doomsday Lemmings update is here, at last!
As mentioned above, six levels from Doomsday Lemmings II were integrated into this (with the rest of the ones created by me being dropped off into the recycle bin (eventually), while it's up to GigaLem what he wants to do with his contributed levels). This brings the pack up to 21 levels total; 7 per rank.
I also removed the talismans, as they didn't feel so right in this pack.
The newly-added levels are:
Outbreak 2 - "Curse Reborn"
Outbreak 7 - "Undead Dipper"
Plague 5 - "Care Package"
Plague 7 - "Braaaaains"
Apocalypse 4 - "A Strange Facility"
Apocalypse 7 - "Release The Horde!"
Since it's no longer the final level, "One Last Lemming" was also renamed to "One Lonely Lemming".
Finally, it also has a minor fix in the filename of the Beast I music. Doomsday Lemmings called this track "beast", while Orig and Extra call it "beasti"; Doomsday Lemmings has now been brought into line with the other two.
Intended solution replays have also been uploaded.