Not sure DIN51524 part2 is achievable with ~ISO VG 15 oils. Non zinc additives(Sulphur phos)) achieve this spec in higher viscosities, I am familiar with the Tellus S range,ISO 32 through to 68.
I find this a new development. Boron CLS Bond will meet desired AW requirements, without ZDDP treats. Additionally, it is also biodegradable and does not become toxic in use, or hydrolyse in the presence of water or at higher temperatures and pressure.