Found a copy of the supplement page online.

The NKDU appears to have been NiCad cell strings with fillers that seal if rotated off 90 degrees. I'm not a chemist or a mechanical engineer (online or elsewhere) but that's my best translation of the electrolyte they want added.

I found where EASA and the FAA are trying to come up with something to solve this.

Most sailplanes aren't going to recharge in flight. That removes almost half the issues related to lithium cells on the front end. The electronics to balance cells are only relevant during the charging process. IMNSHO, they should waive those requirements on anything that does NOT require or provide for in-flight charging at any rate greater than what can be done with PV.

Anyways, thanks for the input. I think I've figured out what I'm going to do and thankfully, I'm not the only one doing it so if I'm wrong, well, I'm wrong in a lot of august company