How to work with files in the ChromeOS My Files app?

Question

I am currently working on a Chrome extension and facing a challenge related to file handling in ChromeOS's My Files application. My objective is to develop functionality that allows users to manipulate files, specifically for encrypting files and appending an .enc extension to the file names.

What I already tried

chrome.fileBrowserHandler

Initially, I attempted to use chrome.fileBrowserHandler, but in the Manifest V3 issue tracker it links to file handlers. Also, I couldn't get the fileBrowserHandler to work with the My Files app.

file_handlers

Subsequently, I explored using file_handlers in the manifest. However, this method appears to restrict operations to files with known MIME types, which limits my ability to universally apply encryption to all file types. Also, I do not know how to actually manipulate the file extension or file content and pass it back from the JavaScript to the file manager.

Questions

I am seeking advice or suggestions on how to effectively approach this problem. Ideally, I need a method to:

1. Allow my extension to manipulate any file type in the My Files application.
2. Perform operations like encryption and rename the file with e.g. an .enc extension.

Any insights or guidance would be greatly appreciated!