I think you're in the minority with your support for the split Tweed but I do admit it's worked in the sense it's given teams something to play for until the end. Trouble is, as stated, playing each other 4 times is monotonous and has led to crowds akin to meaningless games, there's no real visible benefits in terms of quality, it favours the Old Firm far more than anyone else and with it's unequal fixtures it's inherently unfair, which is and should be the main reason for getting rid and bringing in more teams.
I and many like me would go watch Motherwell play friendlies every fortnight if it came to it, we haven't attracted any new fans through it so I would say it's not worked in any fashion bar the one you've quoted. Is that enough to keep it? I don't think so.