If what you want is to engage with clients by doing SMR as a corrective modality Karin is right that you want to study it in depth and take a certification such as the one she mentions, focusing on SMR as a tool within the context of working correctively.
You could also go the route of taking a specific SMR training, such Susan Hitzmann’s MELT method. She is a great instructor (I had her a year ago at Idea World), but the training is expensive, and you might get more out of studying it in the context of corrective exercise, which will offer other tools and applications. You could look at her book if you want a taste of what she offers.
OPTP, who make rollers and such, have a number of rather nice guides for basic rolling. And Idea indeed has had quite a few articles in recent years, which have all been excellent, and Christine is right, all you have to do is look at the library, or your old Idea magazines. This is an ACE article I thought was good: https://www.acefitness.org/certifiednewsarticle/3161/cutting-edge-traini…
You really just need to decide how much you want to learn, because the more you learn the better you will be able to find and address needs with these tools, but the more time, energy, and money you must spend on education and training.