Thank you ;-)
You make a very valid point about the sync folder issue with cloud storage providers. I’m not sure how Boxcryptor et. al. handles this case, but I believe they integrate very differently and more tightly with the host operating system, working as file system filters and similar. We integrate very loosely, which gives us many other advantages, but this can be an issue if you *really* don’t want any plaintext to hit the cloud ever.
I should mention though that it’s not quite like you say. The problem is not opening and working with encrypted files in a cloud service sync folder. The problem is when you drop new unencrypted files in such a folder, until you tell AxCrypt to encrypt them. Working on encrypted files is not a problem (as long as you don’t actually use AxCrypt | Decrypt). Working with files through double-click is safe in this scenario too.
We can probably never, with the current level of operating system integration, guarantee that no files ever hit the cloud since it essentially means we have to interfere quite harshly with the cloud service sync software. It must either never see the real file system, or we must be able to tell it to stop syncing or forbid it to sync files as they appear while they are unencrypted.
We’re certainly aiming at improving this, and many other things!