Could you elaborate a bit on the shareable app instance (or just share links to its documentation)? That sounds really useful but I hadn't heard about this use case before
It’s vscode in your web browser. Run it locally in your dev environment and setup your web server to proxy vscode.your domain.tld to it and boom, you have vscode running in your dev environment that anyone with a link can access.
I haven't used the remote SSH feature, but I have been playing around with GitHub Codespaces through VSCode. Once you have the extension, you can select a repository and it will spin up a virtual workspace for you on their servers. It actually works surprisingly well- tasks like installing node packages is faster than on my local computer and it automatically handles things like setting up a proxy for local web environments.