It is not cheater mldg. Pt is just made to use less wood (or other) material during manufacture, and hence cheaper mldg.
From the front, it gets youthe volume of size, w/o the material cost involved with size.
It's meant for more of the OEM market.
Commonly joined with a 2 or 3 inch corrigated staples perpendicular to the mitre.
If this is a one-off just vise it, glue. Shoot a coupla nails and putty 'em.
If this is a (large) project there are commercial model corru-staple nailer avail.
Or you can get a Hand-held pnumatic gun. But then you have to have an upside down vise.
Biscuit will work, but the cove angle makes it more diff's than vise, glue, nail.