[vbat99]

I didn't know it is that complicated. I  have thought cause the endpoints that are called via HTTPS it's possible with any scripting language.
Just like I brought my very limited knowledge together with Windows PowerShell to get data from ThemovieDB
But I see ThemovieDB offers a dozen ways to access the API and Letterboxd only 3 
https://www.themoviedb.org/documentation...-libraries

Letterboxd is in its infancy with its API, so API Wrappers are still work in progress. With time, someone will write a wrapper I can use in Media Companion

Ok so we have to wait   until letterboxd API supporting more scripting languages or maybe in future you got deeper into Python3.

I won't be using Python in MC. It means another dependency, and cross communicating between Python and VB. Oh, and learning Python programming.

Maybe you have interest to implement a link shortcut for quick visit without clicking scrambling around in the browser same like IMDB,TMDB,TVDB,FANART.TV
The main links are usually this format https://letterboxd.com/film/star-trek-first-contact/
But the links can be autogenerated simple with: https://letterboxd.com/tmdb/199 -> https://letterboxd.com/tmdb/tmdbID

Those shortcut/links for IMDB/TMDb and Fanart.Tv are tabs not buttons.

Adding some function...somewhere... to open the letterboxd site to the specific movie is not a bad idea, but I wouldn't add a new tab just for this. Maybe a button somewhere else, or even in the right-click context menu when right clicking a movie?
So, that is what I have just done.
Currently users can right click a movie and you can choose to open the webpage of the movie at TMDB, If in a Set you can open the Set page at TMDb. AND in the next release, you can open the movie page at LetterBoxD.

Just my 2 cents: I would place the IMDB/TMDB button besides instead toggle, and also FANART.TV beside.
I found out the IMDB/TMDB toggle very late. And just a few months ago i found out how the FANART.TV links working.
If not a Set right click FANART.TV button in Main Windows, if it is a Set this button is dead on right click instead click into the FANART.TV tab, with left click change if Main Movie or Set and right click open the link *gg*
Don't know how to do better but it's really long sentence to explain how it's functional^^

I'd completely forgotten I'd added opening the Fanart.Tv webpage by right clicking the tab header. I don't recall why I set it to not open if the movie was in a collection. Might need to revamp this functionality.

Anyway, your work is much appreciated!  I am the same long time in MC as in Kodi. Thousands of hours.

Always happy to get suggestions, but please don't be offended if suggestions are not taken onboard for development.