is that pretty much it?
Hmm, what you would need to do is speak to BT Broadband (not always the greatest experience, but persevere) You must persuade them to arrange a broadband fault visit, most likely a 'broadband boost' task. Act somewhat dumb, because the second you mention the previous fault they will latch on to that, and that will result in the wrong kind of fault being raised.
"My broadband used to be much quicker, can you fix it please" etc, etc.
When the engineer visits, give them the full details and the suspected diagnosis, E-side previously swapped out to clear a voice fault. That engineer can use a system called the Line Loss Calculator to establish the best E-side range and hopefully, if there's good spares, swap your line on to it and do an SNR reset whilst there too.