likely hitting software-based routing limits

What you did wrong? Nothing … except choosing not the best device for your needs.

You can use a pickup to occasionally transport a dozen bags of cement or a calf but when it comes to bigger tasks, you need proper track and maybe a trailer.

CRSs line should be called SCONSDR - Switch Capable Of Not So Demanding Routing. Even C = CLoud in the CRS line name is a little exaggerated.