I noticed that there is no modifier to give disadvantage on initiative.

There's one to give advantage, is it possible to get the mirror?

I guess you are not wrong for the purposes of having more available modifiers.

I assume this is for some kind of un-fun cursed item. Otherwise, why would you want a disadvantage on initiative modifier?

Building out flaw feats. Feats that players can take at level 1 to gain one real feat or ASI.

Additionally it seems like there should just be feature parity between the advantage and disadvantage modifiers.

I would like to add disadvantage to initiative to a sentient ring.  Can this be added please?

I am looking for this feature as well, cursed items which impose disadvantage on the wearer for other bonuses.

Initiative is a Dexterity roll so adding disadvantage to Dexterity Ability Checks might work?

I was hoping to have this feature available as well.

Same here.  Heavy Encumbrance imposes Disadvantage on all Dexterity Ability checks.    Initiative is a Dexterity Ability check,  thus heavily encumbered Characters have disadvantage on their initiative checks. (which totally makes sense and is realistic BTW,  someone wearing a full plate armor, wielding a tower shield and carry a bag full of crap and a backpack will likely not react as quickly as a leather wearing unencumbered rogue.....

It does not for some reasons.  I did try it.

Anything that provides disadvantage to Dexterity Ability checks also imposes disadvantage to Initiative rolls, which is a Dexterity Ability check (confirmed by Game Designer Jeremy Crawford a few years ago).   Example. Heavily Encumbered characters is a good example.

I need it to add the Side Effect from the Alluring mutagen (You gain disadvantage on initiative rolls)

There is advantage for initiative but not disadvantage. It would help if it is added.

Looks like this one has been brought up multiple times, and I'm poking it yet again.

Is there a better place to be asking/looking for this?

Thanks!