Are the collection of components run in some kind of namespace? Say I run a Pies for Gitlab (which in itself had lots of components), and I run a Pies for Frpd, do they share the same space or are they isolated from each other? Am I maybe overthinking this? Perhaps its just a program manager.

I think they both run as user. But you can put gitlab in a docker

https://www.gnu.org.ua/software/pies/example.php?what=gitlab

https://www.gnu.org.ua/software/pies/manual/Docker-Entrypoin...