Red91; I'm down to my last 4.5 liters of 1330 from a 20L pail I opened in March. Two changes on a 13 matrix and one on a 3 5.3L GMC 1500.
Mono-grade season will be over in the great white north in 8 weeks. I can use up the last of the SAE30 with either 10w30 or 15w40 1300.
I've used Duron 30 and 40 in both my 06 & 11 Duramax, P1200 Zn1350, which is about the same as Delo 400 30 'n 40. In a gasoline engine above say 20F, your 1230 CF-2 might be the ultimate engine oil. HTHS 3.5-3.7 NOACK likely 2-4% I've used HD30 & 40 Castrol in motorcycles, VW Beetles and their 10W40 motorcycle went in my JD 22 hp tractor for a couple of years.
20w50 Castrol MC would be a way around the California oil law.
I read your UOA. What's not to like about your SAE30 program?
Edit as per the last post; TBN or now just "BN" retention, depletion rate is just as important as the BN of the fresh oil.