Adding fixtures or changing layout changes the system's requirements. A successful repair does not establish capacity or suitability for the proposed arrangement.
What the observation means
The model, inlet conditions, discharge route and access may all need a new design assessment. Existing pipe sizes alone do not settle it.
A useful next step
Use the appropriate installer for planned work and keep the current repair scope clear. Do not connect new fixtures during troubleshooting or assume that replacing the pump with a larger-looking unit automatically makes the expansion suitable.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.