Most users simply customize their post processor to implement custom mods like this. I recall John Saunders of NYC CNC doing a video on modding the pp for a custom tool change location. The youtube link below will at least walk you through a high level of customizing your Fusion pp, and get you thinking on how to get to the finish line on this. Its not exactly what you need but will give you insight into modding the PP in Fusion 360.