Reduce the risk of passing a random affix to a legendary.
For example I got a rare unique with 2 LP and I passed to it the two affixes that were not optimal which felt quite underwhelming, as I spent a lot of time finding the optimal exalted item and I may never get the same unique item again.
An idea would be to either farm for something that would let you choose the affix that you want (rare drop from enemies) or something similar (like spending some form of currency for 1 to multiple affixes)
I do agree it can feel frustrating not hitting the 100% correct stats, but i also do think that crafting maybe the most powerful item in the game, should have some kind of risk/reward to it.
Not sure if i would like something this powerful to become “certain”. I would maybe like to see you being able to offer something to craft on the same item again? so using the LP twice, but it would still require you to find another exalted item ofc.