Potions Effects Should Stack

Simply put, effects from potions should stack together. If I drink an eight minute Invisibility Potion, I should be able to immediately drink another eight minute Invisibility Potion, therefore giving me sixteen minutes of Invisibility, instead of just resetting the time to eight minutes. The same would go for potions of any type. Want to have speed two for a while? Drink two or three speed two potions and bam. This may be overpowered in PVP situations, so it should be a toggleable game rule. But in a single player world, if I want to have an effect for an extended period of time, there should be an easier way to do it than have to constantly drink a new potion. It's just a simple quality of life improvement that would make things a bit easier.