Interesting read! I'm on a total of 9 (5 SG and 4 rifle) so far, plus still 1 rifle on my FAC I haven't purchased. No request at the time of granting my coterminus of any additional security beyond our 5 lever locked front door or at the time of variation.
I'll probably make arrangements before the next renewal for something. Costco have some good deals from time to time.
I wonder if they would take into account having some of the firearms stored at my locker in my local club's armoury, as a means of derisking my situation...but on the other hand my license doesn't formally recognise that. Hmm.