On not implementing half the RFCs, this is almost always true... some parts of "standards" are impractical or very difficult to implement, have no practical use or just aren't needed for your use case.

I created a test LMS in 2003 based on SCORM, at the time there really wasn't a good server for the standard... The main point was to be able to test the content which the company was hired to generate. I didn't implement several points of functionality that I just didn't need, didn't care about, and would have been difficult to implement.

That testing LMS turned into an actual product used by several aerospace companies (a few F100's, etc) and was in production for over 15 years. I remain friends with the company owner... It was about 12 years later than someone had an actual course that used one of the features that wasn't implemented... and even then, they only implemented it the half way needed, because it would have been difficult to do the rest.