I just took a brief look at your plan and have a couple of suggestions. Not sure they're the best way to go without thinking about this some more. Hard to see in the attachment but the tail track in the right hand corner (arrowed) is way too short so I'd lengthen it as much as possible.
SP4439
Take a look at this version. Gave you a small 3 track yard & engine/caboose track off the siding. Plus there's no saw backs in your switching area. They may look nice but if you do alot of switching on them you'll soon regret it. As an experienced RR civil engineer told me "if it's on paper, treat the lines like wet noodles".
That tail track is going around a jog in the wall to a small "staging yard/engine and caboose area. The tails of each saw backs will be one or two car spots for industries.
And as for the snap track, i was just using that as a radius reference, In my construction i will be using flex track exclusively.