Sorry, this is not allowed. For every installation you need separate license to use and import demo designs. Please check Themeforest standard license policy https://themeforest.net/licenses/terms/regular .
However, using same license in staging and during live site transfer is allowed. You require to delete staging site after you transfer the site to live site. Keeping simultaneous installation of same license is illegal.
If you want 5 or more licenses then get in touch with our Pre-sales team and they might get you a deal if you purchase 5 or more licenses at a time.