OpenWrt 21.02.1 which guide to use for setting up a repeater

I want to setup a TPlink as repeater with a Wireless connection as feed to/from the rest of my network (and use wired clients connecting to it, no need for WLAN repeating).
As this TPLink will be remote and not easy to reach, I need to be able to also access its LUCI interface through the Wireless connection.
I have done this numerous times in wired mode using one of the LAN or the WAN ports, which all work fine (both with 19.07 and now 21.02.1, so I do understand the differences between the 2 in configuring bridges etc.)

Searching for guides I found several like this old? and this more recent one?. Reading the second it clearly states that IF WDS or 802.11s is supported, by both AP's this is preferred (over relayd). The issue is that my main APs (I want to connect to) are Unifi U6-LR AP's where i do not find if they support WDS and if so, if their WDS is compatible with the one in OpenWRT. But also for all of these guides (relayd, WDS or 802.11s) it is unclear if they are valid or have been validated for use with 21.02.1.

It looks there are 3 options to solve this issue:

  1. relayd
  2. WDS
  3. 802.11s

Is this correct? I am currently biased to try the 802.11s method with 21.02.1 as 802.11.s is an option I can enable in Unifi as well. Any hints/help on how I should setup are appreciated.

  1. WDS (4addr) is not an option while running the unifi firmware.

Thanks for the hint on WDS with Unifi, I will skip that one.
In further search I also found something else which is advertised as "the best" option:
B.A.T.M.A.N.. Anyone experience/comments on this option? Specially in combination with Unifi APs?
It apparently also allows VLANs to travel over wireless, although that is unlikely to work with Unifi as well, nevertheless, I could consider setting up a separate WLAN for this purpose form another OpenWRT device and avoid the potential difficulty towards mix of Unifi and OpenWRT, as I do have multiple VLANs and it is helpfull to bring 2 of them to my remote location.... hmmm... need to think about that.

I got a U6-LR last week and didn’t get WDS and 802.11s to work between OpenWrt and Unifi so I flashed it with OpenWrt. Now everything is working as intended (WDS). I did not try B.A.T.M.A.N.

If you need VLANs on your AP. At least with OpenWrt you could:

  1. Create a WDS AP + STA for every VLAN -> the dirty way - that's how i did it
  2. Use a GRE tunnel
  3. Maybe use Powerline?

Thanks Hudra, good to know I even do not need to try with Unifi FW. Flashing them with OpenWRT is not an option for me, as I have multiple ones and like to manage them through the Unifi Controller. Among things fast roaming seems to work much better with the U6-LR compared to OpenWRT driven AP's in my house (still need to investigate why).
But I am happy to add a special SSID to one of my OpenWRTs and make it a OpenWRT to OpenWRT thing here. I have thought about the dirty way as well. One thing: Can you confirm that you can reach LuCi through the IP assigned to the client in OpenWRT? Because that is essential for me. Happy to try the WDS way....

GRE tunnel i have not looked into, can investigate.

PowerLine? Would be an option as well, i have some installed, but expensive hardware, I can get a decent used TPLink (like a WDR4900) for €25 where an extra client for my powerline would be at least double that price and still have max 2 ethernet lines, and no VLAN support.