I've been using it for a couple of years with Google Drive on Windows, on a near-daily basis, with approximately 300GB across multiple vaults - some very large files, some very small text files (think Obsidian).
I have not encountered any errors / issues / lost data. I do frequently get a message where it tells me it can't lock the vault because it's still "in use", but I just Force Lock and go on with my day.
I second this. Using it with Pcloud. Syncs just fine, and even if it does not fully sync from one computer, I haven't had it corrupt while using the files.
Yes. And that’s why I use Cryptomator too. It’s a nice alternative and I haven’t got issues with it yet. I only store a few GB though but it’s good for me.