This is the way I approach renewals...
For me, an AP is generally a good purchase if I can get two trips out of it, and it is a great purchase if I can get three trips out of it. So, for example, if I go on May for a week, December for a week, and the following April for a week, I’ve gotten really good value from the AP. But I would not renew, because I am probably not going again until December, so if I renew, I would have 8 months unused, and I would get only one trip out of it. So I would wait until December and pay for a new AP, and start the cycle again.
But everyone is different, so you would have to see what works for the way you do Disney.