BUT NOBODY ELSE DOES THIS!
Mastery learning has gone through cycles of popularity. An early peak occurred back in the 1970’s, based partly on the allure of new textbook formats (which did not work as well as promised). After a drop in usage, mastery learning is make a very large comeback during this decade – most often, based on some digital product such as MyMathLab or Aleks. Individual instructors have been running all of their classes based on mastery learning with large numbers of attempts, although few of them have done a ‘self-paced’ thing. (Of course, we have not been ‘self-paced’ since the mid-1970’s; when most of the course must be passed by the end of the semester to avoid paying again, the course is not really self-pace – we are just providing lots of flexibility.
When we search for ‘mastery learning’ in college mathematics, the returns (hits) number about 20 – these represent the entire programs that operate this way. (In fact, LCC does not turn up on this search – unless you count a report that was published in 1982.) However, if you attend a national conference (AMATYC for sure, probably the technology ones too) there are several sessions each year describing a course where the instructor used mastery learning and was happy with it.
Known Colleges with Mastery-Based and/or Self-Paced Developmental Mathematics Programs
So … Lots of people “do mastery learning”. What is truly unusual is the level of freedom our Math Lab students have – it would be quite reasonable to seek ways to limit that freedom to improve success without compromising known advantages (like mastery learning).