In my opinion they should just rebuild the whole thing, but I guess they can't afford to close Space Mountain for that long. They've added breaks and stuff everywhere and at this point it's just too bumpy and rough.
That's cool for Hong Kong, though. They'll have to find new ways to keep HKDL competitive against Shanghai. Losing a ride as precious as Mystic Manor would be truly sad... Or the whole park, for that matter.