I have. Sent them (uncertified) photocopies of my two undergrad diplomas, masters diploma as well as the uni transcripts. All came from Canadian universities. Seems like they have been accepted because my application shows up as 'In process' on the ecas.
I wrote a small cover letter explaining what I was doing, but I suppose it is self-evident.
From what I understand, as long as you have received a diploma for a degree at a university in an English-speaking country and as long as that degree took a year to complete, you are OK.
I've used my degree as my proof and my application is currently in process but i did get that generic Notice of English slip with the book that states that they will test my skills during test taking and verifying the records etc.