Deleting 3D Print Objects inside the game (be it from CaZ or Build Mode) won’t delete them completely from your game, and this could potentially cause some clogging issues, and sometimes give you the error “missing dependencies“ when trying to upload your Zoi or Build to Canvas.
In order to completely get rid of 3D Print Objects from your game:
In your PC, go to Documents > Inzoi > AI Generated > My3DPrinter
From there, you can check the thumbnails and find the object you want to delete, press DEL/SUPR and… voila! the piece is no more 
(And dont forget to permanently delete your Bin from time to time, too!)
Hope this has helped someone~