Maintain User Defined Routes via DNS Name
A script designed to run in Azure Automation which takes a list of DNS names and updates VNet User Defined Routes based on the current IPs.
A config file would contain everything usually defined for a UDR, only with FQDNs instead of IPs. The script would resolve the FQDNs and then create the UDRs. When IPs change new rules would be added, but the rule for the old IP should also be retained until it has not been seen for 24 hours - to allow for transient changes or round robin DNS. This will require the script perform some state tracking.