Major renovation of an extremely large 5 bedroom residence where we are considering using VRF mini split system - existing ducts are being removed due to poor quality and mold.

The question I'm hoping you can help with is if core HVAC has no ducts, what is the best way to do ventilation?

Solution will need to incorporate HRV/ERV as well as filtration & humidity control, and would ideally be combined with the bathroom fan requirements.

The primary issue I see with a typical Fantech HRV solution is you can draw continually from bathroom fans and other design locations, but how to step up the CFM adequately for a specific bathroom when it is in use? Just turning up the HRV might not draw enough from a specific bathroom (especially the one with the highest static pressure).

Is there an elegant and cost effective way to have a point solution?

Am I overthinking it?