[Suggestion] Allow Letter-boxing to be disabled on a per-site basis like we can for Canvas Blocking

New user here. I noticed while configuring my LibreWolf-specific settings that I can make exceptions for individual websites when canvas blocking is enabled globally, but there's no corresponding option for letter-boxing.

It says here in the LibreWolf FAQ that anti-fingerprinting measures aren't especially useful for websites you're already logged into, so I was hoping we could also have the option to disable letter-boxing as well. For me, letter-boxing isn't the most visually appealing way to browse the Internet, and I would enjoy disabling it for the handful of trusted websites I keep myself permanently logged into anyway.

(Also, I'm sorry if this isn't the place for suggestions. I dug around looking for the appropriate place, but this was the closest I could find. Let me know if you need me to move it elsewhere.)