What if you make mods, like a pulley swap, CAI, exhaust etc. and you DON'T disconnect the battery.
Will the PCM relearn and adjust all the same :?:

For major mods like my Jet chip, the PCM took a couple days or 100 miles to get back in step. Disconnecting your battery first is reported to aid this relearning process. It'* not necessary though. "If you build it, it will learn".