I Agree, but. It should go back down to the lowest roll after you imprint the highest roll on gear.
When you find another high roll you can save it in the codex again. Making the low roll go up to the higher roll you found.
This way people wont all have 100 perfect rolls in a couple months. And it will always be a game of find the good rolls for storage till i use them and i have to find them again if i use them.
Im only saying this because that is how Blizzard would like it. They dont like to give the players the power of always having 100% perfect rolls forever.
A better way is to make it so you can store (lets say) 3 rolls for each aspect. And you can choose to use one of the rolls and them it leaves you with one open slot to replace when you find a new roll.
So when you click on an aspect , it has a drop down list so you can choose from the 3 (4, if you count the low roll already in the codex).