Vitamin K2 and Calcium (CAC) Score

This is true and verified - drs had very little nutritional training in medical school.
Evidence based medicine and proven results make it true.
They have shown reversal in heart disease.
DR. DEAN ORNISH. He, along with other researchers, has developed a "lifestyle" program for reversing heart disease. Working with a group of heart patients, ORNISH, has reversed the disease, thru diet, moderate exercise, and stress reduction.

I'm not certain we are using "verified" or "reversal" in the same manner, or even about the same topic.

Verified by independent studies from reputable medical science organizations?

Reversal - of what? Of plaque? Of calcium deposits? Of cholesterol (sure on this).

Here's a quote from the CNN article ... CNN
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"In 1990, internal medicine specialist Dr. Dean Ornish did what no other doctor had been able to do: He published results of a randomized clinical trial that used advanced imagery scans to show coronary artery disease could be reversed with nothing more than diet, exercise, stress reduction and social support."

There are many sites with information about Dr Joel Kahn whose site you linked - I won't link them because you likely would not follow-up with questions since they don't support Dr Kahn's positions.

His own website uses this sort of language - a quote: "A Summa Cum Laude medical school graduate, author, TV personality, and speaker."

And, this, which I understand means he does not accept insurance of any kind - a quote: "The initial one-hour consultation is $600 and follow-up visits are $250 for half an hour."

And, this - more come ons and "packages" - a quote:

"If you want the most comprehensive of evaluations, then you want The Ultimate Heart Check Up. Dr. Kahn is offering The Ultimate Heart Check Up consisting of 2 visits (the first visit is 1 hour, the second is 30 minutes and the second one can be virtual) along with a Carotid Intimal Medial Thickness (CIMT) exam. The package is $1050 and is a unique plan offered only by ​Dr. Kahn.

NEW! The Ultimate Heart Check Up SLEEP package. All of the offerings above plus a home sleep study that can be shipped anywhere in the USA. Up to 50% of Americans suffer undiagnosed moderate to severe obstructive sleep apnea taking a huge toll on health. Find out with the Ultimate heart Check Up SLEEP package at $1350."

I can comment on the massive amount of self promotion he engages in ... it is truly phenomenal - does this not make you suspicious? Why would your own cardiologist, likely trained and experienced not be simply following this doctor's every recommendation?

most doctors are not versed in supplements and won't even entertain the discussion

I would offer that most doctors are well-versed in science, and since there is little, if any science to "supplements" (I'm differentiating these from chemicals your particular body may need more/less of based on something specific), doctors are not interested in them.

There may be exceptions to my broad statement, but I would consider them less supplement, and more proven med. The one that comes immediately to mind is Icosapent ethyl (Vascepa). Related to "fish oil" it appears, according to studies, to provide benefits of reducing triglycerides with fewer heart attacks - and, doctors are aware of the science, and hence prescribe it - but, I don't think it is considered a supplement.

Interestingly, the link below to a Jama Network viewpoint, uses both the term "supplementation" and "treatment" to describe the use of icosapent ethyl.