Sorry if i havent read everything, as this is a lot of catch up to do, but has anyone actually suggested an increased cost to remove RNG system?
Basically all you'd be doing would be adding an item, or adding something to the recipe to increase the cost to lower/remove the RNG factor. Though this would have to be expensive, it would allow people who dont want to gamble their chance, or have extremely bad luck (myself included) to skip it. There are a lot of ways to modify this to suit the design, adding skills that allow this to change from reducing chance of failing, to removing it altogether.
This is actually done in a lot of f2p games via a cash shop, but obviously we're all against that. But such an item doent need a cash shop to exist and be balanced.