For very large templates, using Slave PCs with VE-Pro is the safest, and most reliable way to go, that imho. applies to any DAW that has to deal with a huge track count template.
I love working with Studio One Pro 4, it is very stable (I'm on PC-Windows 8.1 Pro), and for large template work, I use two slave PCs via VE-Pro 6. I was a Cubase Pro 9 user, but the workflow in S1Pro 4 is fast, and wonderful compared to Cubase, I also feel Cubase is getting too clunky, with too many features, and it is slow to open, and save projects, S1Pro 4 just feel a lot snappier for me.
Hopefully Presonus will update it with more Scoring/Orchestral composer related features that will make it more efficient, productive, and suitable for this type of genre. I think the next big upgrade with new features will be Studio One Pro 4.5.