Thank you Claus for being my inspiration receiver (does such a term exist?)
@Luke Harry, Rentlix, everybody else interested:
Regarding the signatures:
First you have to understand that there is a difference between OctagonalEdges, SharpEdges, SharpCorners (only few examples) and even DodecahedralFaceDeletions (no signatures made public).
The signatures are bandaging signatures in first place. If interpreted correctly they are equivalent to truncating schemes. Apply these truncations to a 3x3x3 (or UltimateSkewb if appropriate) and afterwards place extensions on all faces left over from the original puzzle.
I see I have to write an article sometime in the future ... when I have filled up the museum.