I'm sorry you feel I don't have any new information for you. I'm not going to make stuff up just give you the facts which you have researched pretty well yourself.
If you want to see if alternative medicine will help your cat through this then the best option is to find a holistic vet in your area to work with. This site may help you do that
http://www.holisticvetlist.com/#search
I usually look at all the practitioners in the state to see who might be good to work with.
I do know how hard it is to end a bloodline and start over but in my experience it is far better to do that than to continue to produce offspring with problems.
Please press Accept if you find my answer helpful. Want more info? Just reply on your question!
Bonuses for good work are always appreciated!
Thanks for the opportunity to help you!