Cantilever snap-fits print axis
Let's look at the general design.... it is a case... so a box of to halves. And we need some kind of connector...

How about splitting the connector into a separate C-shaped piece? That way the connector clip can be printed with the C to the plane, getting maximum durability out of either pice. You just need to print some short overhangs, the clip going around the central box, possibly in dedicated notches. Also, this is easily removable from the outside with a screwdriver. And easily replaceable. Also, both sides could be identical, if designed in the right way.

Or we use a slot in the lower body, and a Y shaped slot in the top, and make the connectors have a flat hook that matches into the lower body (push in from below) then the split top pushes through the top and latches in... This isn't removable from outside easily.

Third alternative: bolts. If the item inside the box - a PCB? - is going to be bolted to the lower case anyway, why not add extra long screws and have the top case be bolted to the lower case with the same screw that holds the PCB in place? Or, just use a pair of additional bolts and nuts on the corners.

Edit: Recently, Angus aka MakersMuse uploaded a video discussing snap-fit connections and how to make them 3D printable with the example of a backpack buckle.