I think for any school, ED1 means that there are no students admitted so far so there may be more of an open slate. But given the fact that they have an ED2 means they must leave slots for that. I would think it is better to have your best application than to rush.
With ED you are bound to attend if admitted… can your family afford private college tuition (or do you think you would get need based financial aid)
You probably know you can get an idea of need based aid at: Net Price Calculator | Financial Aid | Case Western Reserve University
CWRU will offer the same type of merit aid amounts no matter if you are ED, EA or RD.