I only tell you what we did in the 60s and 70s with these engines. Back then, we used castor of at least 25% content with much higher nitro content than you plan to use. They ran well on the hottest days and I never seized one up. The 36x, as you know, has ball bearings and I never had to replace them.
Fast forward 2008- I flew my Larry Scarinzi hopped up 36xBB on my Sneeker for the first time since 1976. Yes, it required some afterun oil to free it up from the dried varnish, but the engine ran great on a pacifier. After two flights, I decided to let my engine guy look it over.
After cleaning the interior varnish, he was amazed at the condition of the internals. No rust or wear and great compression. All due, nodoubt, to castor.
It's messy, smelly and not popular at any level (R/C or U/C) except with some Ukie flyers who swear it gives the the best protection.