i can’t tell you were are AMR and RSACCH parameters in Huawei : i don’t know this system.
RSACCH does not increase the load of the system, nowhere ! Instead of sending one new SACCH message every 480ms, there is one new SACCH msg every 2*480ms ! In the meanwhile, the same message is sent two times (at t=0 and at t=480ms).
So there is the same amount of SACCH load, with twice less information, each ifo being sent twice.
Enable Repeated FACCH as well, RSACCH and RFACCH are two features that works well together.
RSACCH is only useful when AMR is enabled and you are using “low” codecs. With regular EFR codec, there will be no improvement.