I’d say stage 4 is being the keystone attendee: if you don’t go, the whole thing falls apart. Even if you somehow manage to get out of the meeting, it has to get rescheduled because it “needs” your input. The meeting thus becomes inescapable.
Stage 5 is when everyone else realizes you’re in stage 4 and begins to cater to your availability and preferences. Obviously this is mostly theoretical.
This is actually the beginning of the plot to Sonic Adventure 2. We should be seeing Luigi snowboarding down the streets of San Francisco any day now.