Hi Fr. Simon,Long time since we "spoke" last, how is that mysterios green, did you found it?
anyway, with proper moisture control during application it should take just fine (your mixes above).
Perhaps it will be helpfull to talk it over the phone with Ian (our plasterer). I am not sure if it will be a good idea to post his ph# here, so please call my # (310) 779-5079 and I will give you his.