I would agree, SDs can get a lot bigger than people realise and even if the SD don't intentionally eat them, The endlers may well accidentally get eaten at feeding times if they get to near to the food that an hungry SD is going for
Silver dollars and endlers would be an interesting combination. Silver dollars do need to eat and endlers would make a nice between meals snack for an adult silver dollar. I'm afraid that is all the endlers would be in a situation like that.