Azure-ILB for Multiple IaaS SQL FCI sharing a host - how to correctly set up rules?

Question

My infrastructure department is trying to create a SQL Server failover cluster instance on azure IaaS. These are "plain old" failover clusters, NOT always-on availability groups.

We have 2 VM's, and there are two SQL Server failover cluster instances spanning these VM's. The first SQL FCI was set up some time ago, along with the azure internal load balancer.

Infra is trying to set up the ILB for the second FCI, which was recently installed.

SQL requires that the ILB be set with certain rules. For example, forwarding of port 1434, for the SQL browser service.

When trying to set this rule in the ILB, infra is saying that they cannot do so unless direct server return is enabled, because otherwise the ILB complains that the rule already exists. Which is sort of true, in that it does already exist for the other sql FCI, but that will use a different ILB front end.

There is a guide to setting up multiple SQL clusters behind an ILB here https://www.sios-apac.com/2019/04/multi-instance-sql-server-failover-cluster-with-new-azure-ilb-feature/

In the screenshots associated with the article, there is a rule being set up on the second front end, for port 1434, with direct server return disabled in the screenshot.

Is that just an error in the article? Or have my infrastructure team missed something? Can anyone clarify the process of having two sql server failover cluster instances behind an azure ILB?