Steve, I've wondered the same thing. I may have asked Milen about it before, but if I did, I don't remember the reason, other than it's probably the same reason you can't put a figure on a grade and were stuck with drawing little rectangles to create bridge components, etc. He went through some gyrations to create his tree, but he's never added that to the program.
So, here's what I do:
I swap out the switch for a straight or curve and snip it to size if needed.
In this case, the Ross O-72 curve matches the O-72 switch.
I create my grade. In this example, it's from 0" to 4" for a 3% grade.
Note the curve goes from 2.53" to 2.96".
Next, I replace the curve with the switch. I took care to make sure the switch connected to the 2.53" point, not the 2.96" point, because 2.53" is the elevation the spurs are going to have to be because the elevation of the turnout. I used the Height Shift tool to raise the spurs to 2.53". If you just had a single spur you could create another grade for the spur if you wanted. Note that the other end of the switch is also 2.53 and no longer connects.
So, I change the 2.96 to 2.53. Note that you'll get a ridiculous grade % when you do this. Don't worry about that because when you actually lay the switch, that end will be 2.96" and the grade will be the same as if the curve were there instead of the switch.
I see I got ahead with the Height Shift tool, but it can be done any time and I'm done. I leave the curve there in case I need to recalculate the grade based on edits I make elsewhere.
When you view it in 3D, you can see the switch is flat and the grade is steeper than the other end whereas during installation the switch will be on the grade and it should look just like the curve would. I guess one drawback to placing a switch on a grade is the tendency for faulty points to not stay open or closed. Another is there really should be an easement between the switch and the spur. Depending on the grade, the spur should probably have an easement to something lower than 2.53”.
