That sounds like an interesting project! In the future, I would value an opportunity to learn more about the trial's success if you choose to go with Egnyte. As for your question, you are correct that standard users cannot access Egnyte using a mapped drive. Standard users have web only access. However, if you do choose to use iPads, standard users can access all features of the Egnyte iPad application.
Thank you and please let me know if you have any further questions or suggestions.
I spoke with a member of my team, Filip, and he said he reached out to you to discuss the possibilities of working with Egnyte on this. Please let me know if you have any further questions and I look forward to working with you!