Do Golden charms really work as you think?

They activate on kill, so wouldn't the boost to rarity be almost useless as the rare enemy was already killed BEFORE it activated?

Imagine a "permanent" IR effect that only work for rare or unique enemy.
You need to kill in the first place, right ? It should not work because the enemy already gone ?

Edit
The only case that the effect may not work, is where rarity check is not performed in the process of drop generation, or where the golden charm on the belt is considered "not equipped".

So, from what I can gather from content creator gossip these last few days, apparently gold charms currently do not work favorably to the player, and that GGG are away of this and are planning on changing that, but that the coding required to do so is apparently more complex than they anticipated.

I try not to wear any charms in real life because I almost certain I will lose it any time soon but I have golden charm on all of my characters :P

Hope we get an official comment on it

No they do not. Well not for the killed rare at least.

About minute 2, apparently confirmed by a dev:
https://www.youtube.com/watch?v=uxSjAZebrP0

Sounds like then the charm should last for like 20-30 seconds or so by default

As a non-streamer, non-professional, non-gud gamer I have tested this briefly and in my own testing of 10-12 or so roughly similar waystones and map nodes it feels to me that the rewards were significantly better with no gold charms vs. having 1, 2, or even all three gold charms.

What's the point of a gold charm any way when its only 20% increase.

Just get more survive potential, the golden charm takes 80 whole charges, that's just a waste of time.