If a dynamic port is enabled, you can now make iManage Drive reuse the previously used port number by using the following configuration:

local_rest_service_port: 0

NOTE:

If you have enabled a dynamic port, web extensions do not work. So, users will not be able to sync their files directly from iManage Work. 

From iManage Drive 10.10.0 onwards, iManage Drive for Mac automatically selects a dynamic port if the defined port is in use by another process.