The instrument is more technical in nature than anything else, reading through the explanation confirms that the exemption is only granted because ADF personnel cannot be certified for legal reasons to be approved operators and maintainers of ground based radio aids.
Hence, the exemption is granted to allow the ADF to operate and maintain a small number of radio navaids over their bases.
The only problem with this is if you don't trust the ADF chaps to operate or maintain the gear properly
wouldn't think that that would be an issue, really..