Those are the reasons why I prefer to manage songs of an album in different folders, accepting more complicated approaches of settings transfer (use to do it via track archives, the only way to get all levels and routings included).
I’d like to add
5) Automation can get messy very quick.
Nevertheless I’ve seen colleagues mixing 3 h live sets in a single project. Some things work better/faster that way, others are a pain. Vice versa just the kind of pain is different 
About doubling used disc space: shouldn’t be an issue. Most of us should have multiple TBs plus the same amount of backup discs. Furthermore using .flac reduces file sizes significantly without loss. Magic 