As sad I am to write this, here's the real-life story...

>You would be surprised how many residential customers still have CPE in
>bridge mode and are connecting to PPPoE service using Windows (or any
>other OS) PC using a PPPoE dialer, some of them even using multiple
>parallel PPPoE sessions from multiple computers sitting on the same
>network.

I literally do not know of a single case where somebody around me was running
ppp on Windows 7 (or later) or on a recent version of MacOS. That just doesn't
seem to happen around here (in .nl).

Do ISPs officially support this? Are there ISPs that describe how to put a DSL
model in bridge mode and the configure Windows 10 to connect?

Yes, Telekom Slovenije still runs PPPoE over their fiber network. I was making fun of that 9 years ago (http://blog.ipspace.net/2008/10/internet-access-russian-dolls.html) and not much changed in the meantime.

Unfortunately, some people (including my father) believe that using PPPoE from Windows is more secure than running it from the edge router (aka modem because some people never saw a real modem in their life), so he's running PPPoE from every Windows laptop he has in his house.

How does that work with iphones, android, etc. Do people bridge PPPoE to
wifi and then run PPPoE on a phone or tablet?

Not sure about tablets etc., but that's exactly what he's doing (I think that was the default setup his modem was shipped with anyway... years ago).

How did multiple sessions work with IPv4. Did every session get its own
public IPv4 address using PPP IPCP?

Yes.

How does that work with the /64. Are multiple static /64s assigned to a
particular customer? In the case of multiple /64s, do hosts have sufficiently
stable PPPoE IDs that you can assign the right one to each host?

No idea. I don't want to talk about that setup (because it's breaking down for him occasionally with Windows 10), let alone touch it. Maybe Jan knows more ;))

Hope this doesn't make you depressed...

Ivan