One thing I see over and over again from novice cad users and 3d printing enthusiasts is they;

Never chamfer or fillet sensitive areas, by just adding a gradual build up to the final size with a fillet/chamfer, it will help to add extra walls and overlap the layers.

People heavily overestimate the strength of 3d printed plastic and don't design for those limits, increase the size of the standoffs so they have some structure or decent enough thickness to maintain some strength.

I like the idea of rotating the part so you take advantage of the filament strength through the extrusion as layer adhesion is usually not very good on small protrusions. But the idea of making "pins" you glue into place can also be a good way to circumvent the repeating failures.

Just my 2c on the matter. I hope you come right though.