There are a number of configuration knobs we are dealing here with, which are global configuration, but really should not be. While the configuration layout is hosted by the extensions, they should be instantiated in pcep-topology-provider's namespace, so they can be manipulated for each individual topology and in fact on a per-peer basis.
So we should first deal with BGPCEP-992 to rehost dispatcher configuration and then also rehost the extension configuration. This essentially means that PCEP extensions are pulled in by topology-api, but since they can be configured, that should not be a major problem.