Slow cutting of curves?

Been having a very minor issue when cutting anything with an arc in it such as my arcade bartop side panels.

When cutting the straights its flying along, but the curved fronts seems to slow it right down?

I was thinking it may be the post processor i'm using in Vectric Aspire - i'm using G-Code MM (.tap)

Would switching Post Processor help matters to something such as G-Code mm ARCS (.tap), or maybe something else.

I'm using a CNCXPro as the driver.

Thanks