I believe you are talking about the 48” high electric netting, not an electric fence. They are both extremely effective when used appropriately but they are quite a bit different. I’ve had the 48” high netting for about 3-1/2 years and have not lost a chicken to a land-based predator. My only loss was to an owl one night I was away until 11:00 and was late locking them up.
There is a difference in will one of your dual purpose hens fly over it and can they fly over it. I have about the same hens as you as far as size and even some of the same breeds. I’ve had one adult hen, a Black Australorp, fly over that netting since I got it. That was her flying back in. She slipped out a door to get out. As I was herding her back toward the door to get her back in she casually just flew over the 48” high netting. She cleared it by an easy 12”. If they want to they can fly out but mine just don’t want to.
I have had several juveniles fly out, practically always males about 4 months old. When they are doing their pecking order/dominance fighting thing, if a loser gets caught against the fence he goes vertical to get away. Sometimes he lands outside the netting and does not know how to get back in. A couple of times pullets have done that to get away from an amorous cockerel but never an adult hen or rooster.
One trick I’ve learned to reduce how many cockerels fly out is to avoid sharp corners, plus don’t arrange the netting long and thin. Spread it out as square as you can instead of making it long and narrow.
The electric netting does not work in snow. The snow shorts it out. Once a predator is bitten by it, they learn to avoid it, so it is still a deterrent, but new predators are being born all the time. Dogs are being abandoned in the country. There is definitely a risk if it is grounded out, but for the most part it still acts as a deterrent.
Another problem is that weeks and grass will grow up in it and short it out. Weed eaters and lawn mowers are real dangerous around it, they destroy the netting. How often you have to address that depend on where you live, the season, and how fast weeds and grass grow. At some times of the year it can be as often as 10 to 15 days, sometimes you can go months.