UTF-8 Filenames are fully supported in the Crownpeak CMS.

The Crownpeak CMS as well as Crownpeak managed hosting environments support UTF-8 filenames.  UTF-8 filename support provides the ability to retain UTF-8 characters in published URLS and includes the CMS label, the published filename and the URL for any asset in the CMS.  For CMS instances that have this feature enabled, there are no changes required by the user.  Simply name assets and folders with UTF-8 characters and the CMS will handle the rest.  Some examples are:

Most existing CMS instances already have this featured enabled and all new CMS instances created after January 1st, 2016 should have this featured enabled already. For older CMS instances or if you would like to confirm that your CMS instance is already enabled, please open a support case through https://support.crownpeak.com and we will be happy to confirm. In the event your CMS instance does not have this feature enabled, it will require a conversion to support the longer filenames that are necessary for multi-byte languages. This will be coordinated by Crownpeak and yourself to ensure minimal downtime.

It is recommended, if you wish to utilize UTF-8 filenames, that you also utilize UTF-8 page encoding.  Details for enabling UTF-8 page encoding can be found by going to UTF-8 Encoding for Publishing Packages.  

Related articles:
HTML Unicode (UTF-8) Reference
UTF-8 Encoding for Publishing Packages
Why are there garbage characters on my web page