I've never surveyed NFP'ers about their prayer lives --- maybe somebody should --- though it's such a personal and private part of their faith. It's an issue other people shouldn't be poking their noses into, in my opinion.
But it's presumptuous, as well as a tad insulting, to assume that they aren't doing intense praying when they're abstaining from sex.
My best friend, decades ago when I lived in the Bay Area CA, was a RN who was a "convert" from IUD to NFP. I knew T. and D. pretty well. She confided in me that she, and especially D., both found it difficult to abstain during her fertile time, and confided (with a half-laugh) that they fasted and prayed intensely to quell rather turbulent emotions. They also prayed hard so that their financial and health issues would improve so that they could have more kids.
Their pastor, ironically, gave them no encouragement at all. He kept saying to follow their consciences (well yeah, duh) and if it was so hard they should use contraceptives. T. told this scoundrel in confession that this WAS their shared conscientious choice, and he said "Well, then, if you've got difficulties, you've got yourselves to blame." Excuse me, but what a putz.
They ended up with five, BTW, which is highly unusual in Berkeley, and each one was such a heart-felt gift. They taught me so much about the sanctity of sex. I had never met people so much in love.
Their prayer lives are not the reason they are doing the NFP.
You seem to be missing the point in a big way.
Scripture tells us the only reason for abstinence in marriage is for a short time for the purpose of prayer.
It does NOT endorse it as a family planning method or for any other reason.
THANK YOU! That's exactly what I've been saying. Now, if only the U.S. Archbishop would come to that realization.