There you go, thanks for the picture. Though I don’t think it was designed by a roofer. The metal seems thick for the application where sheet spring steel would hold the shape yet be much thinner to stop water from blowing in the side cracks once the shingle lays back down. You could caulk the big, tapered side gaps but it may stop any water from getting out leaking higher up.
They could have taper ground the perimeter edges of the metal to get the shingle to lay flat, even weld a raised bead (as on sides of static vents) to lift the shingle there to prevent capillary wicking under the shingle bottom edge with all the water running down the dish legs following the bent plate. Or simply install the plate bracket 1” farther down the roof to get the shingle bottom edge away from the water path wicking from above, add a spot of cement to hold it.
A roofer would know you don’t want a sharp edge on the higher metal to cut your shingle if stepped on after being warmed by the sun for a few hours. I’ve walked on shingles, felt something underfoot, only to find under the exposed shingle – a nail or staple (no longer legal here) that was insufficiently driven, or at an angle to cut a hole in the top shingle now. A tapered edge on the plate would solve this as well as any side gaps.
The #8 or so, screw used in the application may work in to the rafter/truss, but not very thick screw threads to grab OSB or plywood sheathing when not in to solid wood. They should recess or countersink the holes for a flush mount larger diameter screw/lag head—same reason as above. A rubber washer under the head or caulking on top is cheap insurance against leaks there.
I haven’t looked at other plates but I hope they are designed better than this one. The lower end is covered by the shingles forcing water under them.........I would think it should be on top the shingle there.
Not blaming you for a generic picture…..just some thoughts.