The Dust earned bonus related to ‘Time Alive’ is capped at around 4 weeks, level is still uncapped.
I believe that this is working incorrectly, it appears to me that players who are dying more often are earning dust faster than those who have been alive longer. There doesn’t seem to be any gradual increase of dust gain the longer you are alive despite what patch notes seem to imply.
It honestly seems like being alive longer slows down your dust gain more than the people who continuously die.