I think the only way to have sustainable P&R is through having 2 tiers of Super League (perhaps 2 leagues of 10). The funding would need to be there for all clubs to be full time working to the same cap and squad structure. The clubs should be encouraged to produce their own players with exemptions against the cap to stop them filling their squads with journeymen. But all this couldn't happen within a fee years, it would have to be a long term plan based on having good sponsorship for the league, and broadcasting deals. But that doesn't come without a good product to start with. So having the 12 year contract in place with IMG makes sense.
Too often the league have looked at the next 3 years and that's it. So then at the end of that period, when things haven't changed, they try something new again. It all needs road mapping so clubs and potential sponsors can see where the game is going.