One of my first snakes, Diamond Lil, was the reason I joined this site all those years ago, because she was starving to death as a non-feeder. When she was so thin you could see her spine I started syringe feeding her ground up pinks. By then I'd tried scenting, braining etc but in this country you can't buy live pinks. I got breeder mice and had to 'grow my own' pinks and she did eventually start eating. Personally, I'd try live pinks before tube feeding every time, but for me it bought Lil time and kept her from dying whilst waiting for live pinks.
I also rehabbed a non-feeder for someone else that came to me in a far worse state, it was 3g and had no muscle tone at all by the time he brought her to me, so I had to tube feed to get her big and strong enough to try live, which she then took to with gusto. when I'd got her feeding reliably on f/t and a good weight she went back to her owner.
I'd tube feed and work on a snake that was a pet again if I was asked, but I don't try special measures on the corns I breed. If they don't feed with simple things like braining, scenting etc I cull them. Not because I'm heartless, but because I only want to sell healthy trouble-free hatchlings. I don't want to risk selling snakes that won't thrive for their new owners. Plus there is always the thought in my mind that non-feeders are perhaps just not meant to survive, that they may have genetic or developmental problems that I don't want to be perpetuated.
One of the respected breeders on here described a 3 strikes policy towards hatchlings, which I thought was a terribly wicked attitude until I experienced the heartache of owning a corn that seemed determined to die in spite of all my efforts to save her. And then realised that for me I feel I have a duty to only sell corns that have a good chance of long and healthy lives for their new owners