Hey,

There was somewhat sound reasoning behind the priority bump when a potion timer gets low. The bump in priority is because a potion with it's long timer has quite a low default priority which means if you have a small maximum number of buffs on screen (i.e. on mobile) your potion can drop off screen to more important buffs. Bumping the priority when it is in the final 30s ensures that the buff icon is there when you need it the most.

I get your concerns however and have placed a feedback job in to add an option to force static priorities for buffs which would mean they retain their relational position. No promises that we will get time to do it before we release it though I'm afraid.