weird item level restrictions

[duvessa]

Requires item level 2+
wands and potions of berserk rage that can get picked up by monsters

Requires item level 3+
artefacts, except for unrandart staves

Requires item level 4+
scrolls of vulnerability, summoning, acquirement, silence, brand weapon, torment, holy word

Requires item level 7+
demon blade, demon trident, demon whip, double sword, eveningstar, executioner's axe, manuals, quick blade, triple crossbow, triple sword

Requires item level 8+
miscellaneous items

Seemingly intended to require item level 7+ but doesn't
fustibalus, lajatang

Ok but why are these weird?
Vaults place items with item levels higher than their depth (yes there are even D:1 vaults do this) so these don't actually stop artefacts and stuff from generating on D:1 they just cause weird breakpoints in item distribution and make it easier for spoiled players to identify scrolls. Yes you could still get a wand kobold or berserk gnoll on d:1 if it found the wand/potion in a vault with bonus item levels.

[sanka]

Well lets forget for a moment the spoilery aspect, assume for example that identification is removed. What is the purpose of these restrictions? For example, what would happen if a character finds a scroll of torment or vulnerability in D1? Most restrictions seems completely arbitrary, like "these items should be rare", but does this additional complexity matters at all?

[Sprucery]

Imo all item level restrictions should be removed. Clean and simple.

(Misc item level 8+? If you find a lamp of fire on D:1 and use it once, it will take a long long time to recharge anyway...)

[Magipi]

What is this "item level" thing? That the stuff cannot spawn on a D floor with lesser levels?