Please give players the OPTION to turn their Season 4 uniques into their reworked versions when Season 5 starts and all Season 4 items will get transfered to Eternal or are already in Eternal.
When player plans to maybe turn the old version of the unique item into the new one, the player should be informed how the result would look like to have a qualified basis on which the player can make the final decision to either convert it into the new version of that unique OR to let it be a “legacy item” from Season 4.
The old and the transformed unique item should have the same number of Greater Affixes in this process. So if you had a 4GA item with maxroll in unique aspect for example, and if you chose to transform it into its reworked version, then the result should be the reworked version with 4GA and a maxroll.
And if the old version had less than 4GA, then the result should be as close as possible to the old version regarding the choice of affixes that shall become Greater Affixes in the resulting reworked version. Of course there will be cases in which the old affix with GA will have nothing in common with the new affixes. In that case any of those new affixes, that have nothing in comming with the old affixes, could become GA.
Of course all this unique item transformation choices by players will only take place on Eternal Realm, not on Seasonal Realm.
Developers, do NOT make the fatal mistake to make all uniques useless on Eternal Realm, because the players have spent so much time to get them. Please!