Update, Feb 24
By way of update, I got all the roundhouse stall floors in, the machine shop in, and all the other tracks leading to the TT. I have tested them and set them into the index program and everything seems to work. I also added all the feeder wires to those tracks. The only problem I found was that when the TT bridge rotates it does not seem to stay at the same elevation. That is, if I stop one end of the bridge at a track it is about 1/32" higher or lower than the other end of the bridge at that same point in about 40 % of the situtations. I have been unable to determine why or how that can happen since the pit seems to be perfictly level. After I noticed that I just programmed the end of the bridge that was at the correct level to stop at the track. Also, I have noticed the "zero" point may be off a bit at times (which means all the preset points are off, since they are all set relative the the zero point), but it is easly corrected, as indicated in the instructions, by just resetting the zero point. Deleting or changing a programmed stop point is just a matter of pushing and holding the the set buttom until it is deleted (Position light - "POS" - comes on), then move to the desired position and press "SET" again until the "POS" light comes back on.
A big part of my apprehension about this part of the layout was that I knew I was trying to put a lot of things into a tight space. I was correct about that and ended up modifying the original plan in a number of small ways. In the end it is going to work about as I had intended as nothing had to be deleted entirely. The turntable itself has turned out to be fairly straight forward, but did require a lot of prior thought and planning. Just take your time. The attached photos show where I am now. Lots more to do in terms of ballast, permanently connecting the wiring, etc., but the main things are in and tested.