Consider the following scenario: I have a shapeless worktable recipe that takes in gravel and uses a sifter in the tool slot to output flint. I want there to be a chance that an iron nugget will be the byproduct of this recipe and .extra(<item:minecraft:iron_nugget>, 0.75) does that just fine. However, I also want there to be a chance that you'll get a gold nugget instead.

Simply tacking on .extra(<item:minecraft:gold_nugget>, 0.25) doesn't accomplish this because the two extra outputs are mutually exclusive and there's the possibility of them both being triggered on the same recipe transaction. This also isn't a sufficient solution for a scenario wherein I want at least one of the two outputs to always transpire, since there's the chance that neither will be triggered.

It would be marvelous if the .extra method accommodated a list of possible outputs that are weighted and rolled on like Minecraft's conventional loot tables.