I don’t think it’s an issue of the tool or the tool created, as others have pointed out, but how would you ever know someone stole your stuff this way?

We still compile our TS to an ES5 target with bootstrap. If you copied a form from our site into the tool, it would be hard for us to tell you took it from us rather than writing it yourself. Maybe if you took some of our more custom card designs, but really, we wouldn’t know that you didn’t just design them yourself similar to how we did because you had the same issues.

if the code for the web app is available (assuming a license that permits it) there is no need to use an extension to copy a component. you got the source code

if the code is not available, very likely you will not have permission to use it.

Don't see a legal usage of this kind of tool in a commercial context. Pretty useful as a learning too though

Just don't say you copied anything

It's up to users of the tool to ensure they comply with the law.

Just like you somehow restrain yourself from photographing someone else's picture and then selling it.