TVUB is for correcting injector latency dependent on voltage
FKVVS is for injector non-linearity
KFKHFM is for MAF non-linearity
Now, you can ignore those guidelines and correct fueling however you want.
But randomly changing things until things are "correct" if you don't know what your underlying issue is probably not the best approach.
I was not all over the place, I fixed my krkte, and it affected my idle.
Than I made mistake and worked with tvub, and it messed up other things.
Trial and error
It is perfect now, lesson learned
