looked interesting, but is around double the price for around max 2 hours viewing per day, with no guaranty of supporting BBC streams. from experience I'll presume they know about this service and are actively blocking their subnet
I'm paying around half the price for unlimited viewing of direct streams (no faffing with client protocols) which come transcoded for home and mobile usage
They are a domestic ISP, so I guess iplayer should work over the service.
[1]: https://www.aa.net.uk/broadband/l2tp-service/