The only packs of mine which haven't gotten an official new formats conversion (and won't be getting one, at least from me) are:
- NeoLemmix Introduction Pack; since I'm no longer managing it
- Lemmings Plus Flashbacks I and II; they've been replaced with Lemmings Plus Compressed, which serves the same purpose and has mostly the same levels as the two Flashback packs combined, with a few tweaks and the addition of some LPV and LPO2 levels. This might also be a good one to consider including, perhaps instead of (rather than as well as) Omega.
All Lemmings Plus packs from III onwards have custom music, which is included in their downloads. There is some overlap; if two packs have a music file with an identical name, the files should be identical too - this is relevant in the case of the two Omega packs (which contain some music from LPIII, and almost all music from LPIV and LPV, respectively, along with one original track each), as well as LPIV which uses one LPIII music. Note that all Lemmings Plus packs, wherever custom music is used, it's in a subfolder of the music folder. NeoLemmix itself supports this, but the editor / Flexi / etc currently do not - make sure the downloader does, or it will break custom music on those packs (although I suspect the downloader couldn't care less about the contents of the files; and simply downloads and extracts some ZIPs; knowing you, probably with a few safety features such as not being able to overwrite EXE files).