I am building a similar utility and will incorporate some of the ideas on this thread.

I agree with use of sed command to update the conf file.

For example the following command sets up miner to privileged mode so it can be controlled through api

sed -i 's_^\("api-allow" : \).*_\1"W:your.remote.ip.address,W:192.168.0.1/16,A:0/0",_' bmminer.conf


The general idea of something I would like to do is to
    - scan local subnet addresses to find ip addresses that respond on port 4028
    - check if the miner has already been "provisioned" with my custom settings
    - run the setup batch file if needed

I don't have all of these steps automated yet but I have a few steps ready.

https://github.com/dfoderick/Mining/blob/master/Antminer/antminerS9api_privileged.sh