My modem actually says that it supports PTM over ADSL instead of ATM. Wow.
I am fairly sure that Burakkucat and I discussed this a good while back, and An Cat Dubh may even have tried it and it did not work with his DSLAM. He is TalkTalk and I have a fairly new (2015-11) BT 21CN Broadcom DSLAM. So that means there is maybe a slim chance for my success? Unlikely though as surely we would have heard about it.
I wonder if it is worth giving it a go?
It might or might not slow down the boot-up process, which is annoyingly longwinded, but maybe that is just training for you, so I perhaps would not leave it on ATM-PTM auto-detect config.
How would I definitively confirm that it is or is not doing PTM? (Brain has died.)