The key to cutting molds like this is to find a tool that's long enough to reach the bottom of the cavity at the deepest part, that's narrow enough to give you vertical corners that have no more than the required radius. The horizontally-oriented corners aren't as big a problem, since you can program extra operations with long tools that have thick shanks but small tips (the shanks might fend you off the corners, requiring some hand work to touch them up). Sometimes it's impossible to find a tool that's long enough and skinny enough to do your finish passes. If you can't increase the corner radii, then the usual alternative is to carve a piece of graphite to the positive form (so those problematic corners are easy to make sharp), and use that to burn the cavity with a sinker EDM machine.