I have to say, i am sooooo not a fan of triggers, personally... its their attitudes and aggressiveness and pure out and out bolshy behaviours that make them soooo antisocial, same as i really not a fan of Malawi Cichlids, however i can sell them really easily because they are stunning fish in the right environment!
We mainly sell Niger Triggers, Picasso Triggers and the absolutely stunning Clown Triggers, all of them complete gits but will hand feed, easy to look after in the right tank, hardy and a great display fish...
I do get sick of people coming into the shop wanting 'reef safe' triggers and insisting that the Niger and Pink Tails are reef safe just because they read so online, I go by the rule of... Triggers are NOT reefsafe until they have been kept with corals and not touched them, and even then i wouldnt completely trust them... Also, would say a LAST fish to add to the tank.
We added a Niger to our reef display tank, he was meant to be the last fish but a customer brought back a fully grown mimic tang that was being a bit of a terror so it got put in, within five minutes it had stripped all the fins off the tang and it took us hours to break down the tank to get the devil out, we got the tang out first and the little stunner grew his fins back within the week with some melafix. The trigger stayed a little longer...
You can never tell, this trigger was proven reef safe when we got him from a customer who had kept him in reef tanks for years with all sorts of fish and no problems, we had him for months with no problems then he started chewing EVERYTHING, rock, corals, fish, glass!! The last straw was when we saw him even looking at the cables and he was outta there! He sold within 24 hours to a tank with a sump and no cables, aparently he has now taken to chewing spraybars, inlet and outlet pipe anything he can chew on.
I dont think even fixing cables to side of tank will help, triggers biting cable will still potentially happen, if anything id worry it made it easier for them to get hold of it and CHOMP, i would think more of getting something like pond hoze or filter hose and fitting it OVER the cable so if it gets bitten, it wont effect the cable but with regular checks, you'd notice if it was being chewed.