It seems in all the crossings I use, the plates don't appear properly.
The road splines cover the grades. Adjusting the height doesn't seem to help.
Are there some that just don't work well graphically or am I just doing something wrong?
Which roads are you using with this crossing? It works best with BNSF50's roads. If you are using a thicker road, such as one of the YARN(ish) variants, it will cover the rails as the road spline connections are set at a height that would cause the thicker roads to cover the tracks.
If you are using the crossing "as-is", that is, directly connected to both road and tracks, adjust the height will have no effect on the relative height of the road to the rails. If you are using an alternative method such as ATLS then yes, you should be able to adjust the height of the crossing without affecting the rail height since they are not connected anymore.
There are very few roads that attach to crossing that do what you want to do. There are some but results are a lot of trial and error. ctclark1 has the best advice by using the ATLS system. With that you not only create the crossings that show the boards and rail but even road intersections that looks correct. The ATLS system is a bit of learning curve but well worth it.
