embed APE

APEs should be able to embedded into presets. Thus, for packs or presets, APEs need not be downloaded seperatley. To save space, saving AVS files would have two options: Standard, and Enhanced. Standard would be the existing kind, and enhanced would have APEs embedded in the file.

Eh?
This would just make every preset larger and duplicate code.

Why not just include the .ape in your pack?

And use nsis so that you can define the path for the ape and the presets yourself, not sure if winzip exe files can do this, but nsis sure can 😁