Hello Grondag The Barbarian!
I have a concern regarding the way lighting affects your darkest moon phases in your mod. I understand that in order for you to accomplish the darkness you inspire to invoke, it requires a bit of work but this 'Vantablack' effect does impose a health risk.

I use a mod called Player companions and I figured I'd send this over to you in hopes you can issue a fix specifically for the way lighting effects (first-player) player model hand, and possibly nametags in question. The context below should give you all the details.

Mods I used that may affect lighting
Betterfog-1.18.2-1.1.1.jar
link
Darkness-forge-mc118-2.0.91.jar
link
Oculus-1.4.3a.jar
link
Player_companions_1.18.2-1.10.0.jar
(version 1.10.0)
Rubidium-0.5.4.jar
link
Starlight-1.0.2+forge.546ae87.jar
link

Originally posted by @Cixon in MarkusBordihn/BOs-Player-Companions#18 (comment)

Hello! I tested this with the new 6.0.0 update on the client only (msg from playercompanion).
This issue also still occurs in a single player environment. I do appreciate the fading, that does help a lot. I'm not epileptic however this does help, I'm sensitive to very sudden light movements and such as I will get a migraine so I thank you a lot for implementing this, I appreciate this a lot.

Here's the previews
Preview 1 (server): https://streamable.com/zlm2yd

Preview 2 (singleplayer): https://streamable.com/428tjs

I think you've done what you can. I do not want you to change too much I think the most you can do is have the untamed fireflies have a low static light source no matter what and add the pulsation light effect so it's never completely dark upon discovering the fireflies. I will need to reach out to the creators of True Darkness to issue some sort of fix. I will mention this ticket.

This issue seems to only have a horrific effect when the moon phases are at the darkest overcast.
Accomplished by setting the time to midnight and then triggering this command 4 times:
/time add 24000