Question: Extension access to local files?

[FFtheBest]

Hi, guys, would like to know if this is normal behavior of Firefox?

my setup, firefox 117 32bit on windows 10, two of them, one with betterfox, one with lepton, both for customization.

I just suddenly found out that, in Violentmonkey, if i make a script to change the font of D:\a\index.html, with "@match file:///*", the css script works. It means, without me click anything, the css in Violentmonkey can access local files.

In chromium, I have to click Extension details -> Allow access to file URLs, in order for the script have access to local index.html.

I initially thought Firefox has forbidden such access.

Should Firefox be expected to behave this way? Or the betterfox and lepton customizations did something to allow such access?

[latipun]

While I have backward issue. I installed dark reader extension.

On chromium, I need to check "Allow access to file URLs" so dark reader can access my PDF file (file:///path-to-my-file.pdf).

But, on Firefox, this extension can't access file URL, so I can't enable dark reader on PDF file.

That button can't be clicked to enable on PDF file, while chromium can (if extension allowed on file URL).

How to allow Firefox extension to access file URL?