The pit slope wall angles are likely to be the same as similar...

The pit slope wall angles are likely to be the same as similar operations in a high rainfall environment and would be based on the consultants advicefrom the PFS completed earlier. They have just announced an exploration program, so there may be an opportunity to lay the wall angle back in the big Awak Mas pit if they find more ore in the high wall.
As for the historic mining they are probably Chinese in origin from a long time ago. They seem to be minor in scale and there has been no illegal mining activity in this area, like has been seen elsewhere in Indonesia.