I don’t use aqbanking, but I would start by looking into those files to see if the content is related to your accounts (I would guess safe to move) or related to the local instance, such as window position and software settings (should be kept local.) Note that kmymoney also keeps config settings in places other than the data file (for example ~/.config/kmymoney/kmymoneyrc and ~/.local/share/kmymoney/kmymoneystaterc) which should be kept local on each PC.