Chrome extension – using the filesystem API

The filesystem API cannot be used by unpacked extensions, which is awfully great for development.

But then the real surprise came when I realized I can’t use it also with my extension packed, because Chrome tells me it cannot find it in the store and is thus greyed out.

Is there any way to actually develop with the filesystem API then?

My goal, in case this is the wrong direction in the first place, is to write some text to a file when some events in the browser happen. The file should be rewritten, rather than creating a new file, which is why I can’t use the downloads API.

Is there any way out of this conundrum?