Stage FRR Configuration Changes
Changes made to the configuration on any FRR Component are applied immediate when hitting the save button. If a large number of changes are necessary, for example to multiple BGP-Neighbor or OSPF Interface configurations, it would trigger massive re-convergence in the Network Infrastructure when it is done in a short period of time. This may impact the availability of large Network topologies. Also, there may be scenarios where it is necessary to change Routing configuration parameters on multiple parts at once to minimize outage or even to ensure connectivity to the Management of the Firewall afterwards, in case there is no management access within a direct connect subnet available.
Long Story short: A consistent runtime configuration of a dynamic routing protocol is important to ensure the availability of any Network. A better approach would be to stage configuration changes and implement an "Apply Changes" Button, like it's done in other configuration sections of pfSense.