Migrating SCCM site to new server

I have a 2309 SCCM environment with SQL installed on a physical server which is beginning to report issues and so we are in the process of building a 2403 site to migrate to. The current prod site is tenant attached, co-management is enabled, and a CMG is configured. I am using ehttp and do not have PKI configured. I have a question about migrating that I cannot figure out.

Several sources state that changing the site code on the clients is the easiest way to point them to a different site. I found a powershell script to do this and it appears to work, though policyagent.log shows warnings related polices linked to the old prod site. I expect this and those appear to be benign. So my questions are:

• After doing this, will clients have issues with co-management or communicating with the CMG on the new site? I have not yet enabled tenant attach, co-management, or a CMG on the new site, so I am unable to test.
• Are there any "gotchas" that I should be aware of?

I am aware of a the practice to do a site recovery of the old site in the new environment which would eliminate the need to rebuild a lot of things and point clients to a new site. However, the requirement were the hostname of the primary site server cannot change is a hard sell to management, in that I cannot perform a "graceful" migration (old and new sites are up at the same, items are copied over to new site or configured, new site is tested, old site is eventually decommissioned.)

Thanks in advance for any comments.