Of course you can decrease the breaking speed of "instant". Just divide by zero. See? This coding stuff isn't that hard.
On a more serious note, if it were possible to have mining fatigue affect the breaking of all objects including "instants", you'd be able to use the effect as a form of world guard, albeit a localized form based on a repeater circuit and a command block to constantly re-apply mining fatigue. Hint: It sure would be nice to have things like world guard in vanilla servers 🙂
Of course you can decrease the breaking speed of "instant". Just divide by zero. See? This coding stuff isn't that hard.
On a more serious note, if it were possible to have mining fatigue affect the breaking of all objects including "instants", you'd be able to use the effect as a form of world guard, albeit a localized form based on a repeater circuit and a command block to constantly re-apply mining fatigue. Hint: It sure would be nice to have things like world guard in vanilla servers 🙂