Attached is the latest line graph I have and also the stats from the modem, the connection has been up for around 3 hours now.
Yup - still no problem with the line. The error rate picked up a little in the last image, but still isn't a problem.
am I correct in assuming that if the SNR margin was lowered for the downstream then my speeds could go higher?
If the speed wasn't capped at 80, the modem would try to sync at a higher speed, and target 6dB. That target SNRM doesn't ever change in FTTC - DLM works in a different way here.
If you look closely, the text part of the images you have shown indicate an attainable speed of 92Mbps. This is usually a slight over-estimate when interleaving is turned off (and a large over-estimate when it is turned on), so you'd probably be able to get around 90Mbps.
Or is this still dependent on what the IP profile is set to?
The other way around - the IP Profile value (at BT) is set once the sync speed is known.