Ubiquiti U6 LR - Support

I see at the following link: https://openwrt.org/toh/ubiquiti/unifi_6_lr
A firmware for this AP. Does this provide more or the same functionality as to the factory firmware?
What I am trying to understand is if the full functionality of OpenWrt is available upon installing the OpenWrt firmware (Converting the AP to a full wireless router.)?

What functions are you looking for, specifically ?

software wise, yes, but there's only one ethernet port, what I can see, so there wouldn't be any wired LAN.

So, Firewall, DDNS, and all of the advanced functionality available in OpenWrt is available. Other than any LAN ports (Only a single which would be used to connect to the ISP/provide power/POE.)
So if using say xFinity/Comcast with a Cable Modem (SB8200) this would be all that is needed?
I can eliminate the OPNSense F/W that I front(edge/border) the U6-LR with now?

Yes, the only limit, sw wise, would be the devices RAM and flash space.