You don't de-prioritize the communication method, but the content of the communication. AS gave pretty clear indication of what that means. You can still be unavailable even if you pick up the phone. It all matters on subject matter of the communication. Is she calling/texting about kids? You get to those in a timely manner as you are also a parent. Other stuff is dependent on the subject matter. For e.g., I only answer stuff around kids and the house and finances (it's all sorted now so it's just about the kids). I only initiate convo if it's about the kids and I stay proactive on that to keep a good co-parenting relationship.
Outside of that, nada. You 180 on your availability by setting boundaries and letting her know that in a polite way. If she's blowing up your phone because she needs you to run some errand for her. Well, you pick up the phone and tell her nicely that you don't do that anymore, instead of ignoring the call. Take charge of what is acceptable and unacceptable to you.
Also, picking up her call on the second ring or the fifth ring is of little consequence. You still had to pick up the phone and deal with whatever she wanted to talk about. Stop focusing on minutae like this and tackle the meat of the issue - the content of the communication.
