Astral Sorcery version : 1.16.4-1.13.9
Forge version: 36.0.39
Resplendent prism ignores zero weights in serverconfig/astralsorcery.toml:
Still get enchantment pointed by red

I cannot reproduce this behavior.
Are you sure you are indeed editing the astralsrocery.toml in that world you're playing in?
not the /defaultconfigs/astralsorcery.toml but the one in /world/serverconfig/astralsorcery.toml (for a server instance) or /saves/<TheWorldName>/serverconfig/astralsorcery.toml (for a specific singleplayer world)?

I see, could you please give me some time to do clear test in new world and report if it is here and my exact actions to reproduce?

I am sorry to say that bug is still here for
Forge 36.1.31
Astral Sorcery 1.16.5-1.13.12
ObserverLib 1.16.5-1.5.3

My astralsorcery.toml's (saves\tst1813\serverconfig) config:

[registries.amulet_enchantments]
	#Defines a whitelist of which enchantments can be rolled and buffed by the enchantment-amulet. The higher the weight, the more likely that roll is selected.Format: <enchantment-registry-name>;<weight>
	amulet_enchantments = ["minecraft:protection;0", "minecraft:fire_protection;0", "minecraft:feather_falling;0", "minecraft:blast_protection;0", "minecraft:projectile_protection;0", "minecraft:respiration;0", "minecraft:aqua_affinity;0", "minecraft:thorns;0", "minecraft:depth_strider;0", "minecraft:frost_walker;0", "minecraft:soul_speed;0", "minecraft:sharpness;0", "minecraft:smite;0", "minecraft:bane_of_arthropods;0", "minecraft:knockback;0", "minecraft:fire_aspect;0", "minecraft:looting;2", "minecraft:sweeping;0", "minecraft:efficiency;0", "minecraft:silk_touch;1", "minecraft:unbreaking;0", "minecraft:fortune;2", "minecraft:power;0", "minecraft:punch;0", "minecraft:flame;0", "minecraft:infinity;0", "minecraft:luck_of_the_sea;0", "minecraft:lure;0", "minecraft:loyalty;0", "minecraft:impaling;0", "minecraft:riptide;0", "minecraft:channeling;0", "minecraft:multishot;0", "minecraft:quick_charge;0", "minecraft:piercing;0", "minecraft:mending;0", "astralsorcery:night_vision;1", "astralsorcery:scorching_heat;0", "twilightforest:fire_react;0", "twilightforest:chill_aura;0", "naturesaura:aura_mending;0", "cyclic:multishot;0", "cyclic:auto_smelt;0", "simplyjetpacks:fuel_efficiency;0", "cofh_core:holding;0", "ensorcellation:magic_protection;0", "ensorcellation:displacement;0", "ensorcellation:fire_rebuke;0", "ensorcellation:frost_rebuke;0", "ensorcellation:air_affinity;0", "ensorcellation:exp_boost;0", "ensorcellation:gourmand;0", "ensorcellation:reach;0", "ensorcellation:vitality;0", "ensorcellation:damage_ender;0", "ensorcellation:damage_illager;0", "ensorcellation:damage_villager;0", "ensorcellation:cavalier;0", "ensorcellation:frost_aspect;0", "ensorcellation:instigating;0", "ensorcellation:leech;0", "ensorcellation:magic_edge;0", "ensorcellation:vorpal;0", "ensorcellation:excavating;0", "ensorcellation:hunter;0", "ensorcellation:quick_draw;0", "ensorcellation:trueshot;0", "ensorcellation:volley;0", "ensorcellation:angler;0", "ensorcellation:pilfering;0", "ensorcellation:furrowing;0", "ensorcellation:tilling;0", "ensorcellation:weeding;0", "ensorcellation:bulwark;0", "ensorcellation:phalanx;0", "ensorcellation:soulbound;0"]

If I delete all enchantments with zero weight and leave amulet_enchantments = ["minecraft:looting;2", "minecraft:silk_touch;1", "minecraft:fortune;2"] it still give me enchantments I deleted from this whitelist.

Still give this:

Closing this one off, did another series of 100 re-rolls today using the below config on the latest releases:

	[registries.amulet_enchantments]
		#Defines a whitelist of which enchantments can be rolled and buffed by the enchantment-amulet. The higher the weight, the more likely that roll is selected.Format: <enchantment-registry-name>;<weight>
		amulet_enchantments = ["minecraft:protection;10", "minecraft:mending;2", "astralsorcery:night_vision;1", "astralsorcery:scorching_heat;1"]

And never got an enchantment outside of that config file for the world EXCEPT when I modified the file without a relaunch first.

MC 1.16.5
Forge 36.1.32
Astral Sorcery 1.132.12
Curios 4.0.5.2
Observerlib 1.5.3
JEI 7.7.0.106

Unable to reproduce.

The issue seems to lie with getWeightedRandomEntry in MiscUtils.java, which doesn't check to see if weights are 0.
https://github.com/HellFirePvP/AstralSorcery/blob/1.16-indev/src/main/java/hellfirepvp/astralsorcery/common/util/MiscUtils.java#L140

(But anyway, why not just remove the enchantments from the config?)

Because they appear even if removed from their mod config, which I of course already did with unwanted enchantments.. They are not unregistred if removed from config. Will it accept float weight of 0.000000001?

Probably, but I have had no issue removing unwanted enactments from the AS config.

With weight like this
[registries.amulet_enchantments] #Defines a whitelist of which enchantments can be rolled and buffed by the enchantment-amulet. The higher the weight, the more likely that roll is selected.Format: <enchantment-registry-name>;<weight> amulet_enchantments = ["minecraft:protection;10000000", "minecraft:fire_protection;5000000", "minecraft:feather_falling;5000000", "minecraft:blast_protection;2000000", "minecraft:projectile_protection;5000000", "minecraft:respiration;2000000", "minecraft:aqua_affinity;2000000", "minecraft:thorns;1000000", "minecraft:depth_strider;2000000", "minecraft:frost_walker;2000000", "minecraft:soul_speed;1000000", "minecraft:sharpness;10000000", "minecraft:smite;5000000", "minecraft:bane_of_arthropods;5000000", "minecraft:knockback;5000000", "minecraft:fire_aspect;2000000", "minecraft:looting;2000000", "minecraft:sweeping;2000000", "minecraft:efficiency;10000000", "minecraft:silk_touch;1000000", "minecraft:unbreaking;5000000", "minecraft:fortune;2000000", "minecraft:power;10000000", "minecraft:punch;2000000", "minecraft:flame;2000000", "minecraft:infinity;1000000", "minecraft:luck_of_the_sea;2000000", "minecraft:lure;2000000", "minecraft:loyalty;5000000", "minecraft:impaling;2000000", "minecraft:riptide;2000000", "minecraft:channeling;1000000", "minecraft:multishot;2000000", "minecraft:quick_charge;5000000", "minecraft:piercing;10000000", "minecraft:mending;2000000", "astralsorcery:night_vision;1000000", "astralsorcery:scorching_heat;1000000", "naturesaura:aura_mending;1", "cyclic:multishot;1", "cyclic:auto_smelt;1", "ensorcellation:exp_boost;1", "ensorcellation:leech;1", "ensorcellation:vorpal;1", "ensorcellation:quick_draw;1", "ensorcellation:trueshot;1", "ensorcellation:soulbound;1", "ensorcellation:damage_villager;1", "ensorcellation:hunter;1", "ensorcellation:bulwark;1", "ensorcellation:magic_protection;1", "ensorcellation:pilfering;1", "ensorcellation:furrowing;1", "ensorcellation:reach;1", "cofh_core:holding;1", "ensorcellation:instigating;1", "ensorcellation:excavating;1", "ensorcellation:angler;1", "ensorcellation:magic_edge;1"]
I still get these lowest weights pretty frequent.

If delete config file, default values are generated from 1 to 10, 1 can't be maximum

Removing the entry should prevent the enchantment from showing up at all. The weight randomization uses Minecraft's "net.minecraft.util.WeightedRandom" function, and I don't have that open in front of me to see if it has limits, or what it checks between. If there is no entry, it cannot select it regardless.

I suspect the insane number you've used is causing the problems. Define "pretty frequently" in that?

edit: are you editing the config in the world save directory for that world you're testing in? If you're editing a copy in defaultconfigs directory, did you remove the one in the world save directory?