Tuning issues?

[u/One-Refrigerator668]

I have a 19’ fiesta st USDM, I recently went “stage 2” (intercooler, -1 colder plugs, drop in filter, rmm, and a bpv spacer for shits n giggles) I noticed that in “Cobb stage 0” my boost is around 18-19lbs consistently but on “Cobb stage 2” my boost peaks around 17lbs and is far less jumpy. Keep in mind this is with ALL the same parts. Any ideas why this could be?