As some ppl here know, S nails were called back due to the COVID-19, so it seemed to them including me that Paley's Options were all unavailable.
But I inquired this question with Paley's assitant who comes from China and he replied to me that Paley said within 2 yrs, S nails can't probably come back but they can substitute S nails with P nails.
So as a practical utilitarianist, I am glad to share the screenshot of this dialogue with you guys:
https://ibb.co/VQ7ZN91
(But not translated so that I can prove myself having not changed the original meanings).