I've been using https://github.com/dundee/gdu for the last few years and started using dua now and really love it. However, one thing that I noticed is that dua doesn't seem to have any kind of caching to speed up results on subsequent runs. gdu seems to use some kind of caching to make it a lot faster on subsequent runs.

Perhaps some form of hashing and hash tables can be used to determine which file-system trees have changed since last run and only calculate those trees again, and use cached results for unchanged trees.