NSH shell has command blquery. It helps to retrieve configuration file values. e.g.
blquery -h <hostname> -e 'config_field_value ("/etc/hosts", 5, 2)'
But for update configuration file values i found only BLPackage could do. And via NSH it requires quite few blcli commands to create and deploy.
Is where any other ways to update configuration files?
Yes, currently NSH does not have a command line utility to generically update configuration files.
Within BSA if you have a Compliance rule or Audit Job to evaluate your configuration files these could be executed via blcli commands and then auto-remediated. Perhaps an option instead of manually building a BLPackage?