Here is a paper[1] written by Andreas Rossberg, specification author of Web Assembly, that discusses the defects in the definition of Standard ML. I believe he tried to address many of these issues with Alice ML[2].

[1] https://people.mpi-sws.org/~rossberg/papers/sml-defects-2013...

[2] https://github.com/aliceml/aliceml

I dabbled with AliceML a long time ago and it was fun!

But I think Rossberg has since moved on, and his latest attempt at a "better ML design" should be 1ML[0].

[0] https://github.com/rossberg/1ml