Is a FRITZ!Box 7530 router (compatible with OpenWRT) will work for VoIP?

My VoIP wallsocket is very similar to this one:

enter image description here

I use a FRITZ!Box 7490 router Avm, with proprietary software which is near to EOL, but it works perfect with this cable:

enter image description here

This cable is a Y cable, one plug goes to phone, the other to internet (I don’t know why is VoIP they use this configuration, I think VoIP use the standard VDSL port).

I want to know something:

  • Is a FRITZ!Box 7530 router (compatible with OpenWRT) will work for VoIP?
  • Do you know a good solution for use a VoIP router VDSL supported by OpenWRT?