If it has a case and it has power, it DOESN'T belong in a more expensive case with more expensive power. Not only does that DFAM waste space in the cab, you're also bumping the actual cost of the DFAM up by the amount of hp it occupies.
Let's see how that works. Let's say, for the sake of the example, that your cab costs $718 (2x Mantis as an example here) and holds a total of 416 hp:
718/416 = $1.73 This is the per-hp cost of housing/powering something in the cab.
60 x 1.73 = $103.80 added to the DFAM's cost.
So, not only does this cost more in the long run, you're also stealing spaces from modules that DO need power and housing...as you've likely noticed. Pull it, enjoy the extra 60 hp you get back, and just use the DFAM in its skiff where it'll be quite happy.