Lighting Improvements require a lot of changes inside client functions and rendering pipeline. Every new game version takes long time to update, that's why v1 is not updated for 1.54. To implement 1.54 and 1.55 support I decided make some changes. These changes will make it easier to update for new versions of the game in the future (unless there is a big update breaking the system). I will release Lighting Improvements v2 after these changes with 1.54 - 1.55 support.
I'm sorry, it takes longer than I expected. I try to have an ETA but this is a mod connected to the game with a lot of changes, it's not possible to know when I am going to face an unexpected problem and how much time it will take to fix.
Also I saw some people complaining about delay because they donated. I said multiple times do not donate until its released. Stop complaining and wait for the release.