Vjversatile

I wanted more manual control than the ATS automatically switching to inverter power when the grid is out. 

My inverter has a critical load output and a smart load output. The critical loads are always connected to the critical load output of the inverter and when there is a power cut the inverter takes over.

The smart load output is used to power the entire house manually if the power is out when solar can generate during the day. I need this to be manual because, i can make sure all Heavy loads like geysers and inductions are not used during this time. I current have a manual changeover to do this switch but looking at options to be able to switch this over remotely and also have a interlock.

Also, i don't want the switchover from grid to Inverter or wise versa instantaneously (Is this even safe for devices, might be since that is what the ATS is doing?), so i plan to use a timer when switching back from inverter power to Grid power

Sorry I by mistake took the 3 heavy connections bottom left as MCBs where you have the loads indication. 

For fridges you need a very fast change over otherwise one could get a lock rotor condition that can at up to 1800W draw cause a overload. For fridges a dead time of 2-3min is ideal. 
@Vjversatile A timer seems fine as you don't need continues power for your loads. Smart switch can work if you can get one with a high enough rating or a basic remote timer and contactor. 

Instant or near-as is actually better as you avoid surging currents - as long as you don't overload the source