Have you considered printing the part with a recess and separate inserts?
or the core in one direction and a cover?
the simplest way to iillustrate this is with a picture.
I have mounted the power supply on a board that stand vertically.
my brackek goes over the whole power supply and thus must be printed so that layers will intersect a hole. when a screw is used this will force the layers apart since the part is weakest at the lamination.
the simple solution is to make the hole oversized so that the screw passes through easily and puts no stress on the layer joins.
and then make a cap
the screw goes into said cap, all "lateral" forces outwards (from the countersink head) are constrained by loops of plastic within the layer, "downward" forces only serve to try to squash layers closed together...
try putting a recess (perhaps 2 - 5 mm) in the top and in the back, then print an insert to exactly match the hole, the part would then be stronger.
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Layer adhesion etc etc]]>
you're advice in that instance would be fine