Indeed! Curious to read the full text of 13-21, but couldn't find it on-line. There are a number of obvious questions like how spec-complaint legacy boosters get a label and how do you register a booster with a carrier when they're a bundler like Millenicom (?), etc.
Reminds me of the "good old days" before the breakup of the Bell Telephone monopoly, when it was illegal to DIY wire a phone extension in your house. The reasons they had were, of course, that unauthorized extensions degraded service and posed a hazard. Technology fixed any problems easily and it's no longer an issue, if it ever was. Same here. Have ill-behaved boosters ever posed a serious problem that couldn't be handled by technology at the cell tower?