Wow! I just noticed the EE Bright Box router now has configuration settings for Modem Mode. The Orange EE Bright Box is indeed a super duper router.
This page allows you to specify the ADSL standards to operate with. You may explicitly set a specific standard, or choose "Automatic" to automatically negotiate with remote DSLAM.
Bit Swapping - Enable Disable
SRA - Enable Disable
To locate the page go > Advanced Set-Up > [Accept] > ADSL Mode