Spitz AX (GL-X3000): Is there a way to disable NAT with IP V4?

[logi]

I ended up using this experimental solution:

GL-X3000 - Bridge Mode WAN IP Passthrough

Hi all, Just got a new GL-X3000 router. I am really happy with its 5G performance in upload and download but I haven’t managed to set it up in bridge mode (WAN IP Passthrough). I would like to set-up the GL-X3000 has a modem only. It will be in front of another more powerful router that will handle the DHCP, port forwarding and the firewall. Is that feature already implemented ? If so, how can I use it ? Did anyone manage to set one up with Openwrt modules such as trelay ?