Regarding the calculation of VMA, we have opted for the classic calculation mode: (distance covered over 6 km / 100). Kiprun Pacer adds 0.5 to the VMA because on the actual day, conditions are not always ideal (wind, rain, fatigue), and an addition of +0.5 is considered to make the VMA more "close" to the true VMA.
However, you can manually adjust it if it does not suit you in the settings tab.