I have looked at the options and discovered the only safe way to access a MYOB company with multiple users, is using MYOB's current products that use their own cloud storage.
Storing a MYOB company file in Dropbox, Google Drive, OneDrive or any other cloud storage will risk data loss and as far as I'm aware, doesn't allow multi-user access.
You could allow remote access (e.g. Teamviewer) to computers in the same office, however I would suggest only storing backups of MYOB data in your own cloud storage.
If you want a better cloud accounting, checkout Xero, I switched to Xero (from Freshbooks) in 2014 and love it. I really enjoyed using Freshbooks as well, but wanted a more comprehensive accounting platform after growing my IT consultancy business.
If you have any other tech related questions, start a chat with me and I will do my best to help.