That's hard to answer. Some would say that you are fine. I've ridden a SS with a quick release without an issue. Since your wheel was not slipping out of place but was just misaligned your's could be fine. It is true that a solid axel with track nut are the best for a slip issue you need to see if your's is even slipping. Your best bet is to ride it around for a bit and test it. If it does need a solid axel, the whole conversion costs about 10$, no big deal.