Security Implications for OME Internet Access

I have a client that would like to allow their techs to access OME from their phones via the mobile app.  The only way they can do it is by reverse-proxying the OME port 2607 directly to the Internet.  Before we consider this option I would like to hear any thoughts about possible security implications of this so that I can make a recommendation to them.  Any input would be appreciated!