Getting a Green Bean built as close a to a stock ts808 as possible. Would d4 and d5 be "stock clipping mode" and d1-3 be the asym clipping mode?
Yes. You got it right. With 3 diodes it's asymmetric - two are the same direction and one is opposite...this was used and patented by Boss/Roland I believe. For a close replica of the 808 use two diodes.