Ok for the -M mgmt IP, you will probably need to run the native IOS-XE version, not the CS version to get this to work. And if the mgmt IP is sticky on a DHCP IP then search for my article about sticky behavior of the native IOS-XE versions. You'll have to go back an forth between an SVI in the DHCP range and then back to the wanted SVI. It's a bit of a mess 😉 But when doing this design please do have a failure check so you can observe the behavior on the C9300 switches with the OSPF default routes.
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