Nice one. Sounds like a sweet setup.
My second server is similar in that the integrated HBA/Raid Controller is limited in it's BIOS Options., So it's running Unraid with every drive set as individual Raid0's. However, my main server i discovered if i just don't set any config and leave all the drives unconfigured then they pass through as if in HBA Mode rather than Raid which was a nice surprise when setting up HexOS.
I did try NGinx and got too many headaches. Ended up going with a Cloudflare Tunnel approach which i found pretty easy to setup, worth a look as i don't believe it requires any specific router setup to work, can implement access policies etc too.
Look forward to seeing how your setup goes 🙂