Check out my timeline. I applied after my EAD expired. My case was approved in 27 days. Don't get your hopes up though it can be totally different for you. It might take way longer than that, some people are past 2 months from expiration without an approval. Just apply and go with the flow. I personally dont think the 120-150 window to apply before expiration is stupid. It makes sense to apply before your EAD expires. I didn't apply on time for financial reasons and am very thankful I got approved super sonic fast.