Rahu and Ketu quadrants and retrograde planets

Hello,

In the Healing Rahu and Ketu 2 course, "Factors that support the healing of Rahu and Ketu" video, Ernst teaches the 4 quadrants:

1. Ketu side of the castle, planets moving towards Ketu, those are the planets we need to resolve our karma with.
2. Rahu side of the castle, planets moving towards Rahu, planets completely dependent on the Rahu quest, won’t offer us much until we move towards the Rahu house. 
3. Ketu side of the castle, planets moving towards Rahu, planets that give a lot of security to the person but that still need to be transformed 
4. Rahu side of the castle, planets whose growth depends on new experiences but that will be swallowed by Ketu, planets that have to be experienced in a new way in order to be completed. 

So, the million dollars question is: How about retrograde planets? For example, Jupiter within the 90 degrees of Rahu so in the Rahu quadrant in the 7th house with Rahu in the 4th house, but Jupiter is retrograde. Do we consider Jupiter moving towards Rahu (quadrant 2) or does it fall into the 4th quadrant?

Thanks!
Mona