To add more mounts you can create a yml file on rancheros like the following:
runcmd:
- sudo mount //windowsFileServer/sharename2 -t cifs -o username=theUserName,password=thePassWordHere /mnt2
Then ‘sudo ros config merge -i moreMounts.yml’ and reboot. You can find the entry in /var/lib/rancher/conf/cloud-config.yml. This was brought to you in part by maik “No risk, no fun.” 
and documentation.