Hi Yiannisel,
The above rack, is that what you are planning to have or did you got that already?
In my opinion, I would either go for an extra rack for some extra space, so you don't have much planning-worries about those 21 HP or, the cheapest solution, remove the DFAM and put that back in its own casing, that saves you here almost one third of your rack space... well at least 60 HP :-)
Kind regards and good luck, Garfield Modular.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads