Well I've been able to login to ECAS now.
No idea when I should have been able to, I noticed I should have selected "England" instead of "UK - British Subject" on the login page
Oddly, it had my home address right but listed my mailing address as somewhere downtown Toronto that I've never lived.
However .. that may have been the address used by my lawyers for my PR. Would they have kept that on file and decided to potentially mail them instead? I hope they've not sent them anything, not dealt with them for almost 3 years.