in matrix filter one or more question code(s) can be set. but it is not possible to use EM for advanced handling.

An example
If you want to have either questionX or QuestionY as filter for questionZ - depending on the result of question A this can't be done.

Ideally the EM should validate in questions Z matrixfilter settings:
{if(questionA=='Y','questionX','questionY')}

or (another example)
(if(questionA=='A','questionY','')}

or
{if(questionA=='B','questionX;questionY','questionX')}

Even if workarounds with js and/or many (hidden) questions as filter are possible this could save a lot of js coding and many fields in the resulting surveys database