Tobias: Your question (as I understood) is related to BOTH my post and Table 1.3 on p. 43 of Bhikkhu Bodhi’s CMA as I explained above.
You wrote: “I think it is remarkable that there is no akusala vipaka directly via the mind-door or via dhammā.”
– That is exactly the issue in my mind.
– Is it not possible that an akusala vipaka directly via the mind-door or via dhammā?
– I think it is not only possible but necesssary. For example, at the cuti-patisandhi moment, a vipaka bring the next bhava can come through any of the six senses. How does an arupavacara Brahma grasp the next bhava at the cuti-patisandhi moment? He has only the mind-door.