Hello Gareth, and welcome to the forum.
Ah, yes, the date-track update mode that never was, but should have been - "Update into the future until the value we're changing becomes something else".
Sadly, the correction of all the date-tracked rows is the only way of doing it via the assignment screen, as far as I know. I have had painful, first-hand experience of this myself recently.
The only other way of doing it would be to write a bit of pl/sql to do this, and have it set up as a concurrent program. Obviously you can make it reasonably dynamic, to the extent that the supplied parameters could include the specific column name that wants to be changed, as well as the old and new values and the date from which this change is to be rippled forwards. And in anticipation of your next question, no I don't have such a script!
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