Thanks for the detailed information! It certainly looks interesting, and relevant to RF engineering in regards to Signal Integrity. I am not entirely familiar with the ins and outs of signal integrity and interconnect characterization. But from my cursory look, it does look like it will fit into scikit-rf (I'll also let the other members chime in here).
The current de-embedding class is more geared towards RFIC on-wafer applications, and there are certainly more applications for de-embedding out there.
If you are familiar with the github workflow and are able to contribute to the project, it will certainly be welcome. Please reach out to the scikit-rf developers/community if you need any guidance with contributing.