@ag_ana - Thank you. Given we have effectively paid upfront the cost of 1Password, I am feeling a little left out of the action.
The rationale as to why I continue to use Dropbox is because I can ask Dropbox to hold my data in a geographical location that is local to me. Your team may be aware of security policies where some (most) governments and corporations have policies in place to ensure sensitive data (such as logins/passwords) are stored in a geographically localized cloud. This is one of the reasons why I haven't switched over to a subscription model.
Having said all that and without having seen how the sharing works, perhaps its worthwhile to consider how this could work for your standalone license customers still using standalone vaults or even allowing us to have a login to 1Password.com for the purpose of this sharing to work for us too. We are your customers too and it is beginning to feel like we are being left out in the cold alley.
The transfer of secrets from Dropbox <-> 1Password Client <--> 1Password.com Cloud would arguably still be secure while the expiration of all secrets will mean we do not abuse your storage contracts on 1Password.com Cloud. To me as an architect, this is all readily achievable. It does open up the possibility of policy violation in my case but as long as there is an expiration tag on all objects and the 1Password team does have automation in place to clean out cached secrets, I am sure I can get this risk assessed as a risk that has an acceptable level of mitigation.