My limited experience with the Kiteaid valve donuts has been of mixed results. If the valve to be re-attached and the bladder film at the valve's position will sit flat with no coning, twisting, bumps, or wrinkles in the area where the donut will contact bladder & valve shoulder, then I have had very good results - the valves remain on and no leaks. Numbers of donut re-attachments done are small, maybe a dozen, and in use just over a year.
The picture below ( apologies in advance - bladders are very difficult to photograph well without a tripod and slow expsoure / no flash ) is an attempt to show a delaminated inflate valve with a nice flat shoulder, and the mating bladder location is also nice and flat. There is a ring of original adhesive or bonding film from the original valve installation which refused to be soaked or steamed off, but it's not a problem, as it's outside the area where the valve donut will adhere to the bladder film.
However if there is coning of the bladder film, the valve shoulder is dished up or one side bent or twisted, then in short order the donut will not seal or keep the valve in place. For cases of valve or bladder distortion, I have had excellent results with Airtime valve traps - approximately 500 installed and in use out there, with only 0.4 % return / failure rate over many years, starting not long after the product was introduced.