There is no "break in" necessary for injectors.. But all older style N54/N63 injectors are shit. As long as you got them replaced with the new style index 11 or higher injectors and calibrated the new values to the DME, you should be set for a while.
'11 BSM 135i DCT - BMS DP, BMS intake, PE res delete, VRSF 7", CP-E CP, JB4 ISO 5_3, 50% E85, CCW Classic
'97 CSM M3/4/5 - GT3582R, TRM IC, Tial 38, Synapse BOV, RallyRoad 300 FP, 60#, TRM tune, Clutchnet st5, Kosei K1 < endless project