If anyone is still interested in having a bulk upload facility, I have raised this as a feature suggestion with SIMS - so if you can, please view and upvote the suggestion if you think it would be useful to you. We pay enough for SIMS, so it would be silly not to have some time saving features implemented by the development team.
Since the move to ESS, they have set up an ideas portal separate to the MyAccount/Customer Support Portal - please follow the link to access my feature suggestion.
https://ess-sims.ideas.aha.io/ideas/SIMS7-I-789