Section "5.3.2. Preparing RHOCP with isolated network interfaces for BGP" includes an example with a NodeNetworkConfigurationPolicy CR.

It includes two routes to the bgpmainnet network (99.99.0.0/16) through the BGP interfaces. The intention is to configure ECMP in those routes.

That example was wrong and ECMP was not properly applied using it. Besides, that configuration would be rejected with certain nmstate versions.

The solution for these issues is to add weights to those routes:
https://github.com/openstack-k8s-operators/architecture/pull/628