I think I made some improvements to your plan. Having both forward and rearward facing sidings mandates that you have a passing siding to allow the engine the runaround its consist in order to spot a car on the siding. Also, a passing siding will allow you to store a train while running another. I use a 1.75" straight before an uncoupler to provided room for the trucks to align and to provide clearance between a parked car and passing traffic.
By starting the siding on the curve lengthens the siding and allows closer spacing of the parallel tracks.
I find the enclosed pdf useful in closing gaps.
Jan