how are you recalibrating injectors? - they are simple solenoids with no drive circuitry to write to..
Im not trying to diss you or anything, but I do repair cars and have access to prop. tools, e.g. when I send a set of GM injectors of delphi brand to be cleaned out - the shop will send it back with a note attached to it giving the exact deviation from specs. I then account that differential into the fuel trim readout. Its normal for injectors to be a bit off spec after a sonic bath. Thats why cleaning is only done once or twice at max during their life.
in BMW, VW and MB - I can actually write the difference into the ECU so future techs do not get confused.
But injector service has been quite rare for me - even in Pakistan, these modern injectors are very long life and being a dead head system with higher filtering done in the fuel line - the injectors work for about 4 times the life of oldschool items.