Simply stack the potions like you would any other item! 
It helps a ton especially in SMPs and long-term game players!  

This addon makes splash potion combat easier and makes potions less annoying to deal with, mainly because your inventory stays uncluttered by potions and you don't have to fill your hotbar with them. 

but that's not all. 

you can drink potions slightly faster now so that splash potions more powerful.

It's a good feature that gives drinkable potions balanced mechanics.
All non-modded potions are supported! (As of 1.19)

There are 4 packs now, each has a different potion stack level! (8/16/32/64)

Images:
these images are from the 16 stack one.

some strength potions stacking:

all potion types stacked to the max.

Known bugs:
 potions do not stack in the brewing stand gui. (can't fix)
For some reason splash potions and lingering potions have a weird offset when you throw them. It's not very bad though. (can't fix either)

Only tested on windows 10, so sorry if there is some device compatibility issues.
Also, no guaranties it works on realms either.  
Any bugs this pack has can't really be fixed by me. I just changed the stack limit for the items, and it doesn't get simpler than that.

Also, I recommend using 8 or 16 versions just because it feels more balanced, but the choice is yours!

subscribe to "Happy1speed In Minecraft" and checkout my channel for more addon content! :J