Dealing with potions in this game is an absolute mess and chore, just like it was back in 2001. This is one major way that Diablo II shows its age considering most modern ARPGs have streamlined this.
I'm requesting an Auto-Potions Mod that will activate once a certain percentage of life or mana is reached. Alternatively, we could use two dedicated keys that will pull from your inventory so you don't have to enter any menus to manually place potions in your belt. For example, if I keymap this function to X and every time I press X a potion is used as long as it is somewhere in your inventory. I'm disappointed that Blizzard didn't even bother with QOL features for potions.
I don't know if this kind of mod is possible since I don't know the limitations, but this would be a highly popular and much needed Quality of Life mod considering how many players I know that hate having to deal with potions in their inventory especially in battle.