I have 3 Omada sites connected trough OpenVPN to single software controller instance on my virtual server. As Omada routers are still not supporting modern OpenVPN I have to manage RasberryPIs as VPN gateways in all sites. This makes bootstrap and failure recovery problematic.

It is safe to just expose software controller's ports to the Internet and point all my Omada devices to it's public IP?

I found no recommendation regarding this setup. 

Regards