Allow locked files and track changes in the collaboration features of Word Online.
We use templates to standardize our deliverables to clients. To do this, we lock the available styles and force track changes by protecting the file with a password. Unfortunately, this is not supported in Word Online. The online collaboration tools work very well, but really should support collaboration with these types of simple constraints. I get it if you exclude this from a lesser license, but if you are paying for the desktop licenses (ex. E5), you should not have limitations with the online product.