Turn sharp edges of low-poly model round in Painter?

Hello experts,

When I am working on building glass material for low-poly models, the sharp edges are preventing me from rich reflections which is crucial for realistic glass rendering results. 

Other than fixing the model, can we optimize this in Painter? I am assuming if I can have Painter find the edges and take advantage of displacement? Frankly don't know how to do it...

Thanks in advance. Or any other advice about making good glass effects on low-poly models are also appreciated.