I started doing that about 15 years ago. I can tell you my filters stopped sucking up my food, and they ended up with less waste between cleaning intervals. I have everything on a timer.
I guess it depends on what types of food you use for the types of fish you have.I have pellets of different sizes and most of them barely even make it to the bottom of the tank let alone getting sucked into the filter due to the fish gobbling them up.
I could see shutting off the filter for a few minutes being practical if flakes or some similar food that blows around the tank are used.
I do shut off my filter during feeding. Once I shut it off. I turn on my lights so I remember that the pump is off. Few times I forget to turn it back on is the down fall also to this situation.
The FX6 shuts down for 1 minute every 12 hours on its own to clear any air
----- Just time your feeding well LOL.
In truth though I have to sometimes over feed my carpintis tank as the little ones get all the food before the bigger slower males can get to any , he's a bit shy
But the food pretty much gets wiped out before it even hits the bottom so have never considered it
I actually worry at times he actually feeds enough
(but that is a derailment that is not required- maybe for another thread)
You can either tun it off/unplug, or like me turn the output down LOW via the output valve(which also slows down the intake) until the fish have finished eating, same difference. I've been doing this with ALL my filters for years as well.
After all, no need in FEEDING your filter "food", that just creates a white "detritus worm" issue, as well as degrading water quality much much faster....