"As you're well aware, a of people, myself included, have issues with EM's Scottish accent."
No problem
I've never heard to many people mention Ewan's Scottish accent within the Critics'Singers Club circle
At that time many people were inging in a whole variety of accents - American, Mummerset - 'Oirish' Mock-Scots'...
Let's face it, most of us were townies singing country songs
There's a myth that Ewan insisted you only sang in your own accent - he lived in London and sang Scots songs - Peggy sang songs from every corner of the U.S. ... they would be daft to have insisted on something they didn't do
The idea of singing songs from your own national cultures came from Alan Lomax, who visted Britain and found everybody (including Ewan and Bert) trying to soun#d like Guthrie or Leadbelly
He accused them of neglecting their own national cultures and they fell into line

Ewan was born of Scottish parents who lived among other Scots families in Salford and took in Scottish lodgers - he would would guess have has a Salford/Scottish accent as a child
When I moved to London he and Peggy gave me a bed for a month and I spent a great deal of time taking to Ewan's mother, Betsy, who lived with them - I quite often had problems understanding the conversation when we gathered together for meals - Ewan lapsed into the accent he grew up with
I come from Liverpool and have been away for over half a century, yet when I talk to family members I slip back into a broad Liverpool accent (to the great amusement of Pat)
Ewaan learned a number of his songs from his parents, so when he decided to sing publicly, he adopted a deliberately neutral accent in order to put them across to an English audience, pretty much as actors do - as a ballad lover, I'm grateful he did
I'm not a Scot, but I've never had any trouble understanding his songs

The Critics Group was set up at the request of a number of singers who weren't happy with what was happy with the club scene
They asked Ewan to hold classes - he refused and instead, evolved a method whereby the members worked on each others singing
Someone would give a performance of say 3 - 4- 5... however many songs, the group would comment on the performance, what worked, what didn't.. and how they singing could be improved
A decision would be reached mutually which particular aspect of the singing might be worked on by members throwing in suggestions, suggestions would be tried and the singer would go off and decide what worked for him/her
Usually, they were asked to bring the song back several weeks later to see whether further work was needed
The system ascertained that everybody in attendance benefited by being required to take part - it worked, often brilliantly

One of the things I took away from the group is that, despite any other problems I may have had, I have never - ever - felt nervous singing in from#nt of an audience.

Ewan also developed a series of singing, voice, relaxation and breathing exercises to develop and expand the voice still work for me nearly half a century later
Most of the meetings were recorded - I have copies here
Jim