Depending on your wiring/electrical skills, I like having a switch for every device (pump timer is switch for pumps) as well as a separate breaker when called for (heat pump, filter pump, booster pump, accessories for example), but one should also use relays so that certain devices can not be allowed to be running unless other devices are actively running. So in a sense, absolute hard wiring is a complete no go. It is unsafe, against code, and provides no control of individual equipment. Switches, Timers, Breakers, and Relays are all part of a properly hardwired pool pad. I have a 100 amp main breaker on the top of my breaker box that kills power to everything on the pad or around the pool.
This doesn't mean that the SWG can't be put on a relay that is only hot when the pump is on with a switch between the relay and the SWG so the SWG can be powered off separately to just turn it off or change a cell, but the relay prevents powering on unless the pump is running. And the reason the switch HAS to be there (unless its on its own breaker) is that the SWG still needs to be switched off when the pump is running in any mode other then Filter! This method also allows each piece of equipment to be on the proper size breaker for its maximum draw. All corded plugs will be eliminated so it will be considered to be properly hardwired with its own switch, relay when needed, and on a proper breaker. One can use the breaker as the device switch if one wants to eliminate the additional switches.