Actually Matt in this case it is not the CAA that is the problem. I have heard that the main problem is with the coasting after GNSS failure due to the aircraft not having IRS position information.
In a RADAR environment you could use DR initially then vectors. But in ZQN with the loss of the GNSS position information in the valley you are up the creak without a paddle.
The Bus and the B737 have about 4 minutes before the IRS Nav Only performance exceeds the RNP, more than enough time to extract from the valley to MSA.