A (better?) alternative to sshfs is Syncthing, which works somewhat like a self-hosted Dropbox; it automatically synchronizes a subtree between computers. I've used it for years, with no problems at all. Maybe it won't handle concurrent edits to the same file well, but that's not something I do.

Meanwhile, the hung mount problem in sshfs can be more or less fixed by giving it the right mount options; perhaps something along the lines of https://github.com/Baughn/machine-config/blob/041e2151dffd8e... will be helpful. Unfortunately these aren't the default.