Which generation of Raspberry Pi do you compare with the Flint 2?
Raspberry Pi 4 probably is more powerful than the Flint 2 in the non-router task, I assume the router always role is a router, and the advance features hand to the NAS with docker or a small but power device (like Raspberry) if you required the perfect performance, like ADGuard, File sharing, etc.
I was wondering if the performance of the Router (in Router Mode) would be powerful enough to manage running Unbound and AGH at the same time compared to having it on a separate device (RPi 4).