The configuration of direct routing will not be that different from CCE setup (when it comes to the cloud side of things). It will require a DNS A Record, pointing to the SBC, which will need a public IP ;)
Thanks for the response. Our 300Mbps fiber connection does not come with a static IP address. It will cost us almost 20x to upgrade to a similar Internet leased line from our ISP that adds a static IP address. However, we do have access to an ExpressRoute connection to our Office 365 tenant via a local VPN. Microsoft told us that CCE was not supported via ExpressRoute. Is that also true for Direct Route?