...from another forum...
Mocking it up by setting track next to each other or placing on marked up paper is probably not as precise as you want for this situation.
I think the suggestions were more about actually laying some track of several feet then running all of your equipment through it to give you a better idea. You already have the track it looks like. In the flesh trials would give you better results than theoretical discussions and mathematical computations.
I didn't have the time today to get all of that equipment out to perform such a test as suggested. But I did do a little abbreviated version. I attached some 22" curves onto either end of the outer radius, and an 18" curve onto the diverging track.
I selected a few freight cars (40 & 50 footers) and ran them back and forth thru this. One even had the old sprung trucks with very small flange wheels . They ran just find.
One thing I did notice is that made a very slight jog at the point end of the turnout. That is a result of that end being slightly straight in nature compared to the other curved portions. Perhaps you can see that here,..
One nice detail on this Peco dbl-curve is that fact that the point rail has a radius built in.
I believe that most any car/loco that can traverse either 18"r or 22"r on their own, will be able to negotiate the respective route of this turnout. I don't think they will be prone to picking the points here, or having trouble with the frog.
I am also feeling good about utilizing 2 of these dbl-curves at the head of the ladder. So the first 2 diverging routes will be 18" radius entrances, and limited to cars/locos that can use them. The rest will be cars/locos that can negotiate 22" curves, which are many.
Longer cars/locos that need at least 24" radius could enter from the mainline track, up the ladder, then duck into a yard track thru the Peco 'small radius' conventional turnouts that make up the ladder, and that have a diverging route of 24" inches.