I had CenturyLink CPE that would crash when a fragmented IPv6 transitted it. That was fun :P. They're also all in on PPPoE and at least on my VDSL2 line, didn't enable RFC 4638 (baby jumbos) to get back to MTU 1500. Pretty happy to be on muni fiber now (although the installation cost was huge).

Ya my router has to do tagged PPPoE through the ONT even though I pay for a static /28. At least I don't have to also do RIP for the subnet like Xfinity requires.

Interestingly, if I pay for their IPTV service the internet side becomes a bare ethernet port over which I can do DHCP for the upstream interface and number the downstream subnet out of my /28.

I have debated paying for TV service as a sanity fee.