OpenVPN-DCO with Linux Kernel 6.12 - not OK

[Oleksa75]

Hello there!
Seems some problem with ovpn-dco patch - its not working

Downloaded patch from source:
https://github.com/CachyOS/kernel-patches/blob/master/6.12/0010-openvpn-dco.patch

I've applied patch for kernel 6.12-rc7
Selected ovpn-dco as module, compiled and installed.

So, I can see module loaded

thinkbox /tmp # lsmod | grep -i vpn
ovpn 102400 0
ip6_udp_tunnel 16384 1 ovpn
udp_tunnel 36864 1 ovpn

And when I start OpenVPN 2.6.12 client, I see message

openvpn[5593]: Note: Kernel support for ovpn-dco missing, disabling data channel offload.
openvpn[5593]: OpenVPN 2.6.12 x86_64-pc-linux-gnu [SSL (OpenSSL)] [COMP_STUB] [EPOLL] [MH/PKTINFO] [AEAD] [DCO]
openvpn[5593]: DCO version: N/A

And driver not applied for tun0 device:

thinkbox /tmp # ethtool -i tun0
driver: tun
version: 1.6
firmware-version:
expansion-rom-version:
bus-info: tun
supports-statistics: no
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

Please, advice - what can be wrong?
And where need to dig to get DCO live?
Thanks!