Is there a digiKam Suggestion Box ?
I wish there was a command in the Keyword Tag right-click menu “Copy this Tag and All of it’s Children”; and then, “Paste Tag and All Children HERE”
With a huge/ very long tag tree, the drag/drop method is very erratic and lurchy and leaves a lot to be desired.
Otherwise, digiKam’s Keyword Tag system is the best out there, bar none.