SWA is not a constant flexing cable designed for suspension, the steel armour can work harden very quickly thus breaking or even the cores so anywhere its subject to wind or repeated movement will effect the structural integrity of the cable. You can get away with it to a certain extent with small cables over small gaps but the larger sizes need support fully along the run.
I fit energy cabling (control and power) to machine wiring looms where the cables are specifically designed to repeatedly move with little structural deteriation or core twisting, its a complex calculation but I can usually tell the customer that a cable I have installed is good for 10million flexes and will last x amount of years, a normal flex can only withstand a few hundred to a thousand flexes of a similar nature before it fails.... its from this angle I would advise you don't use SWA suspended free or to a catinery set-up. If you have ever run cable in when its freezing weather you know how stiff the plastics/pvc become so I wouldn't want the wind swinging any such cable against its anchor points as the sheath would just crack and split.
