I am working with medical health care system in Bosnia and Herzegovina and firewall needs of my project are beyond Digital Ocean Firewal. Cloudflare as protection and performance inproovement combined with Digital ocean is old new big thing and if you yust add "Allow only cloudflare to connect" on VPS firewall that would make it perfect combination. Beside this yust leave space for adding client IP yust like Microsoft did on Azure DB so I connect do my thing and remove ip.
FEEL IT d.o.o. Maglaj