The problem when importing is that Cabbage will not update the import files text when users move things around. So if you put widgets into an include file and then move them around after they have been included, those positions won't be saved when you exit. Therefore it's better to organise your widgets into plants.
I'm not saying it's stupid. But I do think it's a good idea to discourage certain practices. We see this all the time in programming. New features are constantly introduced in languages to help discourage people from dong things that can lead to problems. Smart pointers in C++ are a good example. For now you can put your plants within a plant, within a plant, within a plant. But do so at your own risk you'll never hear my encourage someone to do it! And keep in mind, that while you can move the parent of nested plants around, you can't resize the children unless it's a basic child-parent setup.
Safety ends at level But I will try to add some kind of obvious warning to resizing of a plant's children only work in the basic child-parent setup.
I just tested that here and it seems to work fine. Can you check out some of the GEN examples and see if they behave as you'd expect. That should rule out Cabbage problems then. Cheers.
 Victor just sent me on the latest OSX beta. I've updated the OSX package. Do a reinstall and you should have the latest beta version of Csound. Run from the command line to confirm. I think you may have to modify your code a little in order to avail of the changes Victor made.