I would recommend DFP-34X-2C2 SFP because it's cheaper, active firmware development, PVID...
Thank you very much @Anime4000 for your great work.
After reading your GitHub repository, with a bit of trial and error and after installing the firmware version V1.0-220527, I managed to get
my recently purchased SFP XPON ONU DFP-34X-2C2 working perfectly with my Internet provider (ISP) O2 from Spain . I bought it from the seller Fibershow @ AliExpress, and it took about two weeks to arrive at home in Madrid (Spain).
It had firmware V1.0-220304 from stock, so I didn't have to do anything to enter the PLOAM in hexadecimal (20 characters). It was very easy to get O5 ONU State, but unfortunately it didn't authenticate and connect PPPoE interface to have Internet. But surprisingly, it did get IP address 10.25.x.x for VoIP (VLAN3), being able to make and receive calls to the landline (phone). So undoubtedly the SFP XPON ONU was authenticated to the OLT, but for some reason it was not able to authenticate and connect PPPoE interface to have access to the Internet.
The next step was to modify the OCMI identity to try to fool the OLT, without success.
The next step was to update to firmware V1.0-220414, and try both fake OCMI and stock OMCI, with no success.
Finally, I tried updating to firmware V1.0-220527 downloaded from GitHub Anime4000 repository, with stock OMCI and it was a success, since I had authentication, PPPoE connection and Internet (VLAN6). Also VOIP (VLAN3) works perfectly. I use Mikrotik RB4011iGS+5HacQ2HnD-IN using its SFP+ port, and RouterOS 7.2.3
It does not have any special configuration to make it work, with the OCMI and the stock GPON configuration (except the PLOAM, obviously)
The performance of the Internet connection is as expected, there is no difference with the previous ONU UFiber Nano G. My FTTH subscription is 600 Mbps.
Unfortunately, I cannot test if Movistar+ IPTV (VLAN2) works, since O2 does not have IPTV.
I hope this information helps other people in a similar situation, especially those who want to use O2 Spain or Movistar
And once again give my
thanks to Anime4000 for their great contribution to my success. I definitely recommend their GitHub
https://github.com/Anime4000/RTL960x/