Good luck in the search for wormholes. I am puzzled by your criteria for what is believable and what is not. The only evidence that I can offer to date is the high spin of black holes after billions of years of slowdown. Not conclusive I know. There is also the model proposed for the origin of supermassive black holes. Again, not conclusive but a better explanation than the other ad hoc processes.
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Dave Proffitt
http://blackholeinside.co.uk