Maybe your RX470 have Samsung memory which allow for Hs rates above 1000 without many tricks. My RX580, they have hynix memory, which works well for Ethereum mining but not as well for Cryptonight mining.
Anyway I am not giving up on SRB, it is just that it seems it needs more parameters than Cast and that it is a long learning curve.
Cheers.
i never used cast, but looking at the parameters, how does one set intensity and stuff like that? I don't see any option for tuning or optimisation?