I’d recommend what I’ve recommended to you before.
Use Shinobi, ZoneMinder, BlueIris to manage your video streams. I know with Shinobi and strongly suspect you can with the other two that you can export your video feeds as a JPEG stream. Use that with an Image element on your sitemap with a reasonable refresh rate.
matt1’s suggestion of setting up a VPN to your home network and not going though myopenhab.org is also a great solution.
I use both approaches and I use Tasker to automatically connect to my VPN when I’m on any network besides my home network so I don’t end up wasting battery and network bandwidth going out and coming back in over VPN when I’m on my home network.
For those interested in Stuart’s SSH tunneling approach, see Remote Access Using SSH Tunnel on Android.