I don't really know a great deal about the later empire.
In the later empire, there were more changes to the law.
I'm not an expert, but I do happen to have a few books about the later empire.
Many, if not most, involved venationes, and in the later Empire some may have been only that.
The later Roman Empire was in a sense a network of cities.
Others point to the heavy fiscal difficulties and political turmoil of the later Empire that made it difficult to continue traditional policy.
As in the later Roman Empire, it remained a military office.
Some grew into considerable settlements and were fortified during the later Empire.
During the later empire, the name Calvisius is sometimes found as a cognomen.
Military service in the later empire continued to be salaried and professional for Rome's regular troops.