What to expect, week by honest week
Weeks one and two are stubble physics: hair short enough to be rigid, angled into skin, maximally itchy. Oil helps the skin but cannot change the geometry. This is the quitting window; most men who shave do it here, one week before it gets better on its own.
Weeks three through six the hairs lengthen enough to bend rather than stab, and patchiness starts filling from behind — cheek growth lags chin growth by weeks, which is normal and not a verdict. This is where the brush earns its place, training direction while the hair is still persuadable.
Past two months you have a beard rather than a project, and the routine shifts from defense to maintenance: oil daily, wash twice weekly, trim the escapees, and reassess length goals quarterly. A beard at six months is a different material than a beard at six weeks — drier at the tips, heavier, more opinionated — and your oil amount should grow with it, roughly a drop per extra inch.