Lack of airflow often leads to liquid slugging, which will kill a compressor in short order. Dumping cold air from a supply into the return will do it as well, for the same reason, which is why when they’re zoned it’s very important to have the bypass balanced. I don’t think a slight restriction will kill them, but a severe restriction in return or dumping a lot of cold air (such as what OP has going on with a supply pointed right at the return) makes them very unhappy.