I agree that medical staff offices are generally clueless about the specifics of subspecialty credentialling. The only people who know are physicians within the specialty. I have no clue about ortho spine, ortho sports, or foot and ankle training. Neither do most physicians sitting on credentialling committees. I think most of the motivation to be ACTA certified will come from the practitioners themselves who want the highest possible credentials for themselves. Why go through all the effort to learn that material and not get the paper?
This happened with PTE certification long before it became a requirement at most places. AFAIK, PTE certification is still not required where I work and yet I’m the only testamur and everybody else is certified. It is not required yet everybody did it anyway. I stopped doing cardiac at the end of last year, but I’m willing to bet all my partners who continue to practice cardiac anesthesia will become ACTA certified. They are just the kind of people who go beyond the minimum requirements. It won’t be relegated to just academics.