Regretfully, we are not familiar with Yoast Snippet plugin so we could not compare. It would be best to use only one snippet plugin though.
Regarding the Snippet extension's compatibility with WPML, nothing in the documentation states that it is compatible with WPML. But, I believe it should work. I'm sorry but we, as support, could not test this as WPML is a paid plugin.
Thank you for understanding.