[Pharo-project] Opal Decompiler status

I see that the OCFakeDecompiler which uses the old and horrible (*) Decompiler is still in use. Though, IRBytecodeDecompiler seems already quite advanced. Could we have a primer on what remains to do on the Opal front? (*) just look number of inst vars, count how many times their state change, and measure average method length for an approximate definition of horrible