I had to order 2 more counterweights to mount the Takahashi scope (it's so much heavier then the Celestron EDGE scope!) Once I had those, I could work on mounting it and connecting it. I wanted to move all the equipment boxes (Robofocus box, Dew Heater box, Power distribution, USB hub). Then I only have 2 cables through the mount which should make this easier. Also, when moving the scope outside or back, I would have to carry the mount and the scope separately - and that would be much easier if I only have to connect 2 cables.
Went to Home Tepot to buy fitting screws and some metal sheets. I screwed them into the bottom of the accessory ring:
And then mounted all boxes on the side with velcro tape:
The metal is a little too flimsy and bends slightly. Either I have to buy thicker sheets or alternatively I could try to 3D print a perfectly fitting piece. But for now, all boxes are now on the scope - and they are on the axis, i.e. don't contribute too much to the momentum of the scope.
When I used the scope, I noticed that I couldn't pull out the focuser enough - the cables were too tights. Of course, with this focuser I have to leave some slack in the cables:
I never had that issue with the Schmidt-Cassegrain scope ...