Maybe even also have a chance to upgrade the Sealed Affix a level from max T4 to T5 or by one level of the Sealed Affix if it isn’t T4 already. Just a Thought as I was pondering since we have already paid the cost to have them sealed on the item in the first place! This could be the ONLY condition in which a sealed affix could be upgraded to T5 or 1 tier higher than it currently is 
Edit: Additionally, if it so happens that RNG didn’t do us well after the item obtained a sealed affix, and we have 0 forging potential left afterwards, by default, the Chest after beating Julra should at least recognize that the item has 4 total affixes and will randomly transfer those qualifying affixes onto the legendary depending on the LP of the Unique. What you all think of this? Fair?