Does the 40% FGTS penalty apply to every without-cause dismissal?
Yes, Art. 18, §1 of Lei 8.036/1990 makes the 40% penalty mandatory whenever the employer dismisses without cause; it does not apply to a voluntary resignation or a for-cause dismissal, and drops to half, 20%, in the mutual-agreement termination created by Lei 13.467/2017.
Why does 2 years of tenure not double the 1-year notice period?
Because the formula adds a fixed 30 days plus 3 days per full year beyond the first, so moving from 1 to 2 years adds only 3 days, reaching 33; several years of tenure need to accumulate before notice grows proportionally to time worked.
Do proportional vacation and the 13th salary apply without a full accrual period?
Yes, in a without-cause dismissal the vacation and 13th-salary twelfths are paid proportionally to the months worked in the current cycle; this stops applying only in a for-cause dismissal, where TST Súmula 171 and Art. 3 of Lei 4.090/1962 rule out both proportional payments.