Keep in mind the 21EAP4s have a design flaw that resulted in a short life - less than two years. Long before the issues you mention show up. For example, here's a dead 21EAP4 and yoke that look brand new.
No, it would not test good if it had issues. I'm not saying all 21EAP4s are duds or doomed to early failure - just that that had a high failure rate initially. I replaced this dead EAP4 with another that tested like new. It had no label - so I don't know who made it though.