you're not fixing the distortive incentives with this scheme, just transforming them. 'capitation' incentivizes hoarding of patients, most obviously by incentivizing the minimization of treatment times and associated costs but also through outright fraud (by falsifying records, etc.). so you're essentially trying to maximize patient outcomes by capping costs, which is a terrible proxy metric all around.
to actually improve healthcare, we'd need to increase spending per person (by an order of magnitude or more, using more team-based medical care rather than 1-on-1), for not only direct care costs, but also research and development. what we absolutely need none of is deadweight losses, like profit-maximizing medical administration, big pharma, and the whole medical insurance industry. medical 'insurance' has become a complete misnomer, as it no longer serves to mitigate the distasterous effects of low probability, high impact events, but as a socialization of routine medical care, which is not insurance at all.