pfSense

https://forum.netgate.com/topic/153911/setting-host-uniq-for-pppoe:
"My ISP uses the host-uniq part of the PPPoE PADI packet to authenticate the system before any communication. How can I set this value in PfSense?"

it's already supported by FreeBSD: https://reviews.freebsd.org/D9270

from https://www.freebsd.org/cgi/man.cgi?query=ng_pppoe&apropos=0&sektion=0&manpath=FreeBSD+11.3-RELEASE&arch=default&format=html:

NGM_PPPOE_CONNECT (pppoe_connect)
      Tell a nominated newly created hook that its session should enter
      the state machine as a client.  It must be newly created and a ser-
      vice name can    be given as an argument.  It is    legal to specify a
      zero-length service name, this is common on some DSL setups.    It is
      possible to request a    connection to a    specific access    concentrator,
      and/or set a specific    Host-Uniq tag, required    by some    Internet
      providers, using the "[AC-Name][Host-Uniq|]Service-Name" syntax.  To
      set a    binary Host-Uniq, it must be encoded as    a hexadecimal lower-
      case string and prefixed with    "0x", for example "0x6d792d746167" is
      equivalent to    "my-tag".  A session request packet will be broadcast
      on the Ethernet.  This command uses the ngpppoe_init_data structure
      shown    below.    For example, this init data argument can be used to
      connect to "my-isp" service with "my-host" uniq tag, accepting only
      "remote-ac" as access    concentrator:

        "remote-ac\my-host|my-isp" 

need WebGUI option