If it conducts electricity, it can be cut with EDM.
Cutting speed is dependent on wire size, material density, material quality, material thickness, and complexity of the cut.
"Good" aluminum will cut fairly fast.
"Bad" aluminum may not cut at all due to non-conductive inclusions.
Anodized aluminum cannot be cut as the anodize is non-conductive.
It is rare to find material with a lot of non-conductive trash in it, but it does happen.