Currently I always run rdictcc with an alias:
rlwrap rdictcc --directory $XDG_DATA_HOME/dictcc
Would be good if that weren't necessary - I don't mind the exact name of the directory, but it would be nice if XDG base directory standard is respected, maybe with fallback to the home directory path.
Yes, you are right, that would make much sense.
If you would like to work on that and provide a patch, that would be very welcome. Otherwise, I'll eventually come to it but don't hold your breadth.