Any way to use -n when parallel fuzzing?

[vivin]

I am trying to perform parallel fuzzing with the main instance fuzzing a binary with regular instrumentation, and the child instances fuzzing a binary with custom instrumentation. But this fails because I set AFL_INST_RATIO to 1 when I instrument those binaries with my custom instrumentation. I tried setting both AFL_SKIP_BIN_CHECK and AFL_DUMB_FORKSRV to 1 and that doesn't work either. When I tried to use -n, it says that -n cannot be used in conjunction with -M and -S.