Well, I was just pointing out that when someone texts you a direct question, and you don't respond, that causes the other person to be frustrated because they don't know that you are working on it. A simple "I'll check" can eliminate that.
Look, I understand what it's like to dread communication from your ex. Spew is so unpleasant. I gradually trained mine to only use email. If he called and I mistakenly answered (I had an old flip phone at the time and couldn't see who was calling) our phone call would "mysteriously" get cut off in the middle. If he called right back I'd say "sorry I must be driving through a coverage hole" and the minute he started spewing again, we'd get "mysteriously" cut off again!
If he texted I responded with email. And when he emails my answers are brief and to the point, I don't encourage chit chat. I answer what needs to be answered and don't respond to anything else he says.