Trends for "teaching-only" jobs?

In our newest "how can we help you?" thread, a reader asks:

I’m interested in trends for teaching-only jobs. I know that Lecturer/VAP positions have been around for many years, and I’ve held these myself. In recent years, I’ve noticed an increased number of ads for “Instructional Assistant Professors,” “Assistant Teaching Professors,” etc. Some of these seem to have more expectation of permanency than the Lecturer positions, and I’ve seen some with promotion schedules. But the position titles are not consistently applied.

Have others observed this trend? Do others perceive that these are more permanent than Lecturers? Those of you chairing searches or involved in obtaining permission to run searches, what considerations prompt you to seek a teaching-only position? I wonder, for instance if they are less common in schools with graduate programs, because perhaps the grad students fill some of those needs. And what determines the position title?

I ask because, after a decade in the profession, teaching philosophy is my greatest strength. As I make some decisions about my future, I’d love to hear about trends in teaching-only jobs.

I've definitely noticed this trend, though I'm not sure what best explains it.

Do any readers have any helpful insights?